Glossary
- Page ID
- 34285
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|---|---|---|---|---|---|
| (Eg. "Genetic, Hereditary, DNA ...") | (Eg. "Relating to genes or heredity") |  |
The infamous double helix | https://bio.libretexts.org/ | CC-BY-SA; Delmar Larsen |
| Word(s) | Definition | Image | Caption | Link | Source |
|---|---|---|---|---|---|
| cell | smallest independently functioning unit of all organisms; in animals, a cell contains cytoplasm, composed of fluid and organelles | ||||
| organ | functionally distinct structure composed of two or more types of tissues | ||||
| organ system | group of organs that work together to carry out a particular function | ||||
| organism | living being that has a cellular structure and that can independently perform all physiologic functions necessary for life | ||||
| tissue | group of similar or closely related cells that act together to perform a specific function | ||||
| anabolism | assembly of more complex molecules from simpler molecules | ||||
| catabolism | breaking down of more complex molecules into simpler molecules | ||||
| development | changes an organism goes through during its life | ||||
| differentiation | process by which unspecialized cells become specialized in structure and function | ||||
| growth | process of increasing in size | ||||
| metabolism | sum of all of the body’s chemical reactions | ||||
| renewal | process by which worn-out cells are replaced | ||||
| reproduction | process by which new organisms are generated | ||||
| responsiveness | ability of an organisms or a system to adjust to changes in conditions | ||||
| control center | compares values to their normal range; deviations cause the activation of an effector | ||||
| effector | organ that can cause a change in a value | ||||
| negative feedback | homeostatic mechanism that tends to stabilize an upset in the body’s physiological condition by preventing an excessive response to a stimulus, typically as the stimulus is removed | ||||
| normal range | range of values around the set point that do not cause a reaction by the control center | ||||
| positive feedback | mechanism that intensifies a change in the body’s physiological condition in response to a stimulus | ||||
| sensor | (also, receptor) reports a monitored physiological value to the control center | ||||
| set point | ideal value for a physiological parameter; the level or small range within which a physiological parameter such as blood pressure is stable and optimally healthful, that is, within its parameters of homeostasis | ||||
| abdominopelvic cavity | division of the anterior (ventral) cavity that houses the abdominal and pelvic viscera | ||||
| anatomical position | standard reference position used for describing locations and directions on the human body | ||||
| anterior | describes the front or direction toward the front of the body; also referred to as ventral | ||||
| anterior cavity | larger body cavity located anterior to the posterior (dorsal) body cavity; includes the serous membrane-lined pleural cavities for the lungs, pericardial cavity for the heart, and peritoneal cavity for the abdominal and pelvic organs; also referred to as ventral cavity | ||||
| caudal | describes a position below or lower than another part of the body proper; near or toward the tail (in humans, the coccyx, or lowest part of the spinal column); also referred to as inferior | ||||
| cranial | describes a position above or higher than another part of the body proper; also referred to as superior | ||||
| cranial cavity | division of the posterior (dorsal) cavity that houses the brain | ||||
| deep | describes a position farther from the surface of the body | ||||
| distal | describes a position farther from the point of attachment or the trunk of the body | ||||
| dorsal | describes the back or direction toward the back of the body; also referred to as posterior | ||||
| dorsal cavity | posterior body cavity that houses the brain and spinal cord; also referred to the posterior body cavity | ||||
| frontal plane | two-dimensional, vertical plane that divides the body or organ into anterior and posterior portions | ||||
| inferior | describes a position below or lower than another part of the body proper; near or toward the tail (in humans, the coccyx, or lowest part of the spinal column); also referred to as caudal | ||||
| lateral | describes the side or direction toward the side of the body | ||||
| medial | describes the middle or direction toward the middle of the body | ||||
| pericardium | sac that encloses the heart | ||||
| peritoneum | serous membrane that lines the abdominopelvic cavity and covers the organs found there | ||||
| plane | imaginary two-dimensional surface that passes through the body | ||||
| pleura | serous membrane that lines the pleural cavity and covers the lungs | ||||
| posterior | describes the back or direction toward the back of the body; also referred to as dorsal | ||||
| posterior cavity | posterior body cavity that houses the brain and spinal cord; also referred to as dorsal cavity | ||||
| prone | face down | ||||
| proximal | describes a position nearer to the point of attachment or the trunk of the body | ||||
| sagittal plane | two-dimensional, vertical plane that divides the body or organ into right and left sides | ||||
| section | in anatomy, a single flat surface of a three-dimensional structure that has been cut through | ||||
| serous membrane | membrane that covers organs and reduces friction; also referred to as serosa | ||||
| serosa | membrane that covers organs and reduces friction; also referred to as serous membrane | ||||
| spinal cavity | division of the dorsal cavity that houses the spinal cord; also referred to as vertebral cavity | ||||
| superficial | describes a position nearer to the surface of the body | ||||
| superior | describes a position above or higher than another part of the body proper; also referred to as cranial | ||||
| supine | face up | ||||
| thoracic cavity | division of the anterior (ventral) cavity that houses the heart, lungs, esophagus, and trachea | ||||
| transverse plane | two-dimensional, horizontal plane that divides the body or organ into superior and inferior portions | ||||
| ventral | describes the front or direction toward the front of the body; also referred to as anterior | ||||
| ventral cavity | larger body cavity located anterior to the posterior (dorsal) body cavity; includes the serous membrane-lined pleural cavities for the lungs, pericardial cavity for the heart, and peritoneal cavity for the abdominal and pelvic organs; also referred to as anterior body cavity | ||||
| computed tomography (CT) | medical imaging technique in which a computer-enhanced cross-sectional X-ray image is obtained | ||||
| magnetic resonance imaging (MRI) | medical imaging technique in which a device generates a magnetic field to obtain detailed sectional images of the internal structures of the body | ||||
| positron emission tomography (PET) | medical imaging technique in which radiopharmaceuticals are traced to reveal metabolic and physiological functions in tissues | ||||
| ultrasonography | application of ultrasonic waves to visualize subcutaneous body structures such as tendons and organs | ||||
| X-ray | form of high energy electromagnetic radiation with a short wavelength capable of penetrating solids and ionizing gases; used in medicine as a diagnostic aid to visualize body structures such as bones | ||||
| active transport | form of transport across the cell membrane that requires input of cellular energy | ||||
| amphipathic | describes a molecule that exhibits a difference in polarity between its two ends, resulting in a difference in water solubility | ||||
| cell membrane | membrane surrounding all animal cells, composed of a lipid bilayer interspersed with various molecules; also known as plasma membrane | ||||
| channel protein | membrane-spanning protein that has an inner pore which allows the passage of one or more substances | ||||
| concentration gradient | difference in the concentration of a substance between two regions | ||||
| diffusion | movement of a substance from an area of higher concentration to one of lower concentration | ||||
| electrical gradient | difference in the electrical charge (potential) between two regions | ||||
| endocytosis | import of material into the cell by formation of a membrane-bound vesicle | ||||
| exocytosis | export of a substance out of a cell by formation of a membrane-bound vesicle | ||||
| extracellular fluid (ECF) | fluid exterior to cells; includes the interstitial fluid, blood plasma, and fluid found in other reservoirs in the body | ||||
| facilitated diffusion | diffusion of a substance with the aid of a membrane protein | ||||
| glycocalyx | coating of sugar molecules that surrounds the cell membrane | ||||
| glycoprotein | protein that has one or more carbohydrates attached | ||||
| hydrophilic | describes a substance or structure attracted to water | ||||
| hydrophobic | describes a substance or structure repelled by water | ||||
| hypertonic | describes a solution concentration that is higher than a reference concentration | ||||
| hypotonic | describes a solution concentration that is lower than a reference concentration | ||||
| integral protein | membrane-associated protein that spans the entire width of the lipid bilayer | ||||
| interstitial fluid (IF) | fluid in the small spaces between cells not contained within blood vessels | ||||
| intracellular fluid (ICF) | fluid in the cytosol of cells | ||||
| isotonic | describes a solution concentration that is the same as a reference concentration | ||||
| ligand | molecule that binds with specificity to a specific receptor molecule | ||||
| osmosis | diffusion of molecules down their concentration across a selectively permeable membrane | ||||
| passive transport | form of transport across the cell membrane that does not require input of cellular energy | ||||
| peripheral protein | membrane-associated protein that does not span the width of the lipid bilayer, but is attached peripherally to integral proteins, membrane lipids, or other components of the membrane | ||||
| phagocytosis | endocytosis of large particles | ||||
| pinocytosis | endocytosis of fluid | ||||
| receptor | protein molecule that contains a binding site for another specific molecule (called a ligand) | ||||
| receptor-mediated endocytosis | endocytosis of ligands attached to membrane-bound receptors | ||||
| selective permeability | feature of any barrier that allows certain substances to cross but excludes others | ||||
| sodium-potassium pump | (also, Na+/K+ ATP-ase) membrane-embedded protein pump that uses ATP to move Na+ out of a cell and K+ into the cell | ||||
| vesicle | membrane-bound structure that contains materials within or outside of the cell | ||||
| autolysis | breakdown of cells by their own enzymatic action | ||||
| autophagy | lysosomal breakdown of a cell’s own components | ||||
| centriole | small, self-replicating organelle that provides the origin for microtubule growth and moves DNA during cell division | ||||
| cilia | small appendage on certain cells formed by microtubules and modified for movement of materials across the cellular surface | ||||
| cytoplasm | internal material between the cell membrane and nucleus of a cell, mainly consisting of a water-based fluid called cytosol, within which are all the other organelles and cellular solute and suspended materials | ||||
| cytoskeleton | “skeleton” of a cell; formed by rod-like proteins that support the cell’s shape and provide, among other functions, locomotive abilities | ||||
| cytosol | clear, semi-fluid medium of the cytoplasm, made up mostly of water | ||||
| endoplasmic reticulum (ER) | cellular organelle that consists of interconnected membrane-bound tubules, which may or may not be associated with ribosomes (rough type or smooth type, respectively) | ||||
| flagellum | appendage on certain cells formed by microtubules and modified for movement | ||||
| Golgi apparatus | cellular organelle formed by a series of flattened, membrane-bound sacs that functions in protein modification, tagging, packaging, and transport | ||||
| intermediate filament | type of cytoskeletal filament made of keratin, characterized by an intermediate thickness, and playing a role in resisting cellular tension | ||||
| lysosome | membrane-bound cellular organelle originating from the Golgi apparatus and containing digestive enzymes | ||||
| microfilament | the thinnest of the cytoskeletal filaments; composed of actin subunits that function in muscle contraction and cellular structural support | ||||
| microtubule | the thickest of the cytoskeletal filaments, composed of tubulin subunits that function in cellular movement and structural support | ||||
| mitochondrion | one of the cellular organelles bound by a double lipid bilayer that function primarily in the production of cellular energy (ATP) | ||||
| mutation | change in the nucleotide sequence in a gene within a cell’s DNA | ||||
| nucleus | cell’s central organelle; contains the cell’s DNA | ||||
| organelle | any of several different types of membrane-enclosed specialized structures in the cell that perform specific functions for the cell | ||||
| peroxisome | membrane-bound organelle that contains enzymes primarily responsible for detoxifying harmful substances | ||||
| reactive oxygen species (ROS) | a group of extremely reactive peroxides and oxygen-containing radicals that may contribute to cellular damage | ||||
| ribosome | cellular organelle that functions in protein synthesis | ||||
| chromatin | substance consisting of DNA and associated proteins | ||||
| chromosome | condensed version of chromatin | ||||
| histone | family of proteins that associate with DNA in the nucleus to form chromatin | ||||
| nuclear envelope | membrane that surrounds the nucleus; consisting of a double lipid-bilayer | ||||
| nuclear pore | one of the small, protein-lined openings found scattered throughout the nuclear envelope | ||||
| nucleolus | small region of the nucleus that functions in ribosome synthesis | ||||
| nucleosome | unit of chromatin consisting of a DNA strand wrapped around histone proteins | ||||
| connective tissue | type of tissue that serves to hold in place, connect, and integrate the body’s organs and systems | ||||
| connective tissue membrane | connective tissue that encapsulates organs and lines movable joints | ||||
| cutaneous membrane | skin; epithelial tissue made up of a stratified squamous epithelial cells that cover the outside of the body | ||||
| ectoderm | outermost embryonic germ layer from which the epidermis and the nervous tissue derive | ||||
| endoderm | innermost embryonic germ layer from which most of the digestive system and lower respiratory system derive | ||||
| epithelial membrane | epithelium attached to a layer of connective tissue | ||||
| epithelial tissue | type of tissue that serves primarily as a covering or lining of body parts, protecting the body; it also functions in absorption, transport, and secretion | ||||
| histology | microscopic study of tissue architecture, organization, and function | ||||
| lamina propria | areolar connective tissue underlying a mucous membrane | ||||
| mesoderm | middle embryonic germ layer from which connective tissue, muscle tissue, and some epithelial tissue derive | ||||
| mucous membrane | tissue membrane that is covered by protective mucous and lines tissue exposed to the outside environment | ||||
| muscle tissue | type of tissue that is capable of contracting and generating tension in response to stimulation; produces movement. | ||||
| nervous tissue | type of tissue that is capable of sending and receiving impulses through electrochemical signals. | ||||
| serous membrane | type of tissue membrane that lines body cavities and lubricates them with serous fluid | ||||
| synovial membrane | connective tissue membrane that lines the cavities of freely movable joints, producing synovial fluid for lubrication | ||||
| tissue | group of cells that are similar in form and perform related functions | ||||
| tissue membrane | thin layer or sheet of cells that covers the outside of the body, organs, and internal cavities | ||||
| totipotent | embryonic cells that have the ability to differentiate into any type of cell and organ in the body | ||||
| anchoring junction | mechanically attaches adjacent cells to each other or to the basement membrane | ||||
| apical | that part of a cell or tissue which, in general, faces an open space | ||||
| apocrine secretion | release of a substance along with the apical portion of the cell | ||||
| basal lamina | thin extracellular layer that lies underneath epithelial cells and separates them from other tissues | ||||
| basement membrane | in epithelial tissue, a thin layer of fibrous material that anchors the epithelial tissue to the underlying connective tissue; made up of the basal lamina and reticular lamina | ||||
| cell junction | point of cell-to-cell contact that connects one cell to another in a tissue | ||||
| endocrine gland | groups of cells that release chemical signals into the intercellular fluid to be picked up and transported to their target organs by blood | ||||
| endothelium | tissue that lines vessels of the lymphatic and cardiovascular system, made up of a simple squamous epithelium | ||||
| exocrine gland | group of epithelial cells that secrete substances through ducts that open to the skin or to internal body surfaces that lead to the exterior of the body | ||||
| gap junction | allows cytoplasmic communications to occur between cells | ||||
| goblet cell | unicellular gland found in columnar epithelium that secretes mucous | ||||
| holocrine secretion | release of a substance caused by the rupture of a gland cell, which becomes part of the secretion | ||||
| merocrine secretion | release of a substance from a gland via exocytosis | ||||
| mesothelium | simple squamous epithelial tissue which covers the major body cavities and is the epithelial portion of serous membranes | ||||
| mucous gland | group of cells that secrete mucous, a thick, slippery substance that keeps tissues moist and acts as a lubricant | ||||
| pseudostratified columnar epithelium | tissue that consists of a single layer of irregularly shaped and sized cells that give the appearance of multiple layers; found in ducts of certain glands and the upper respiratory tract | ||||
| reticular lamina | matrix containing collagen and elastin secreted by connective tissue; a component of the basement membrane | ||||
| serous gland | group of cells within the serous membrane that secrete a lubricating substance onto the surface | ||||
| simple columnar epithelium | tissue that consists of a single layer of column-like cells; promotes secretion and absorption in tissues and organs | ||||
| simple cuboidal epithelium | tissue that consists of a single layer of cube-shaped cells; promotes secretion and absorption in ducts and tubules | ||||
| simple squamous epithelium | tissue that consists of a single layer of flat scale-like cells; promotes diffusion and filtration across surface | ||||
| stratified columnar epithelium | tissue that consists of two or more layers of column-like cells, contains glands and is found in some ducts | ||||
| stratified cuboidal epithelium | tissue that consists of two or more layers of cube-shaped cells, found in some ducts | ||||
| stratified squamous epithelium | tissue that consists of multiple layers of cells with the most apical being flat scale-like cells; protects surfaces from abrasion | ||||
| tight junction | forms an impermeable barrier between cells | ||||
| transitional epithelium | form of stratified epithelium found in the urinary tract, characterized by an apical layer of cells that change shape in response to the presence of urine | ||||
| adipocytes | lipid storage cells | ||||
| adipose tissue | specialized areolar tissue rich in stored fat | ||||
| areolar tissue | (also, loose connective tissue) a type of connective tissue proper that shows little specialization with cells dispersed in the matrix | ||||
| chondrocytes | cells of the cartilage | ||||
| collagen fiber | flexible fibrous proteins that give connective tissue tensile strength | ||||
| connective tissue proper | connective tissue containing a viscous matrix, fibers, and cells. | ||||
| deep fascia | layer of dense connective tissue surrounding muscles, bones, and nerves | ||||
| dense connective tissue | connective tissue proper that contains many fibers that provide both elasticity and protection | ||||
| elastic cartilage | type of cartilage, with elastin as the major protein, characterized by rigid support as well as elasticity | ||||
| elastic fiber | fibrous protein within connective tissue that contains a high percentage of the protein elastin that allows the fibers to stretch and return to original size | ||||
| fibroblast | most abundant cell type in connective tissue, secretes protein fibers and matrix into the extracellular space | ||||
| fibrocartilage | tough form of cartilage, made of thick bundles of collagen fibers embedded in chondroitin sulfate ground substance | ||||
| fibrocyte | less active form of fibroblast | ||||
| fluid connective tissue | specialized cells that circulate in a watery fluid containing salts, nutrients, and dissolved proteins | ||||
| ground substance | fluid or semi-fluid portion of the matrix | ||||
| hyaline cartilage | most common type of cartilage, smooth and made of short collagen fibers embedded in a chondroitin sulfate ground substance | ||||
| lacunae | (singular = lacuna) small spaces in bone or cartilage tissue that cells occupy | ||||
| loose connective tissue | (also, areolar tissue) type of connective tissue proper that shows little specialization with cells dispersed in the matrix | ||||
| matrix | extracellular material which is produced by the cells embedded in it, containing ground substance and fibers | ||||
| mesenchymal cell | adult stem cell from which most connective tissue cells are derived | ||||
| mesenchyme | embryonic tissue from which connective tissue cells derive | ||||
| mucous connective tissue | specialized loose connective tissue present in the umbilical cord | ||||
| parenchyma | functional cells of a gland or organ, in contrast with the supportive or connective tissue of a gland or organ | ||||
| reticular fiber | fine fibrous protein, made of collagen subunits, which cross-link to form supporting “nets” within connective tissue | ||||
| reticular tissue | type of loose connective tissue that provides a supportive framework to soft organs, such as lymphatic tissue, spleen, and the liver | ||||
| supportive connective tissue | type of connective tissue that provides strength to the body and protects soft tissue | ||||
| subserous fascia | layer of connective tissues between the deep fascia and serous membranes superficial fascia | ||||
| superficial fascia | layer of connective tissues found deep to the cutaneous membrane | ||||
| cardiac muscle | heart muscle, under involuntary control, composed of striated cells that attach to form fibers, each cell contains a single nucleus, contracts autonomously | ||||
| myocyte | muscle cells | ||||
| skeletal muscle | usually attached to bone, under voluntary control, each cell is a fiber that is multinucleated and striated | ||||
| smooth muscle | under involuntary control, moves internal organs, cells contain a single nucleus, are spindle-shaped, and do not appear striated; each cell is a fiber | ||||
| striation | alignment of parallel actin and myosin filaments which form a banded pattern | ||||
| astrocyte | star-shaped cell in the central nervous system that regulates ions and uptake and/or breakdown of some neurotransmitters and contributes to the formation of the blood-brain barrier | ||||
| myelin | layer of lipid inside some neuroglial cells that wraps around the axons of some neurons | ||||
| neuroglia | supportive neural cells | ||||
| neuron | excitable neural cell that transfer nerve impulses | ||||
| oligodendrocyte | neuroglial cell that produces myelin in the brain | ||||
| Schwann cell | neuroglial cell that produces myelin in the peripheral nervous system | ||||
| apoptosis | programmed cell death | ||||
| atrophy | loss of mass and function | ||||
| clotting | also called coagulation; complex process by which blood components form a plug to stop bleeding | ||||
| histamine | chemical compound released by mast cells in response to injury that causes vasodilation and endothelium permeability | ||||
| inflammation | response of tissue to injury | ||||
| necrosis | accidental death of cells and tissues | ||||
| primary union | edges of a wound are close enough together to promote healing without the use of stitches to hold them close | ||||
| secondary union | wound healing facilitated by wound contraction | ||||
| vasodilation | widening of blood vessels | ||||
| wound contraction | process whereby the borders of a wound are physically drawn together | ||||
| Meissner corpuscle | (also, tactile corpuscle) receptor in the skin that responds to light touch | ||||
| Pacinian corpuscle | (also, lamellated corpuscle) receptor in the skin that responds to vibration | ||||
| rickets | disease in children caused by vitamin D deficiency, which leads to the weakening of bones | ||||
| vitamin D | compound that aids absorption of calcium and phosphates in the intestine to improve bone health | ||||
| albinism | genetic disorder that affects the skin, in which there is no melanin production | ||||
| basal cell | type of stem cell found in the stratum basale and in the hair matrix that continually undergoes cell division, producing the keratinocytes of the epidermis | ||||
| dermal papilla | (plural = dermal papillae) extension of the papillary layer of the dermis that increases surface contact between the epidermis and dermis | ||||
| dermis | layer of skin between the epidermis and hypodermis, composed mainly of connective tissue and containing blood vessels, hair follicles, sweat glands, and other structures | ||||
| desmosome | structure that forms an impermeable junction between cells | ||||
| elastin fibers | fibers made of the protein elastin that increase the elasticity of the dermis | ||||
| eleiden | clear protein-bound lipid found in the stratum lucidum that is derived from keratohyalin and helps to prevent water loss | ||||
| epidermis | outermost tissue layer of the skin | ||||
| hypodermis | connective tissue connecting the integument to the underlying bone and muscle | ||||
| integumentary system | skin and its accessory structures | ||||
| keratin | type of structural protein that gives skin, hair, and nails its hard, water-resistant properties | ||||
| keratinocyte | cell that produces keratin and is the most predominant type of cell found in the epidermis | ||||
| keratohyalin | granulated protein found in the stratum granulosum | ||||
| Langerhans cell | specialized dendritic cell found in the stratum spinosum that functions as a macrophage | ||||
| melanin | pigment that determines the color of hair and skin | ||||
| melanocyte | cell found in the stratum basale of the epidermis that produces the pigment melanin | ||||
| melanosome | intercellular vesicle that transfers melanin from melanocytes into keratinocytes of the epidermis | ||||
| Merkel cell | receptor cell in the stratum basale of the epidermis that responds to the sense of touch | ||||
| papillary layer | superficial layer of the dermis, made of loose, areolar connective tissue | ||||
| reticular layer | deeper layer of the dermis; it has a reticulated appearance due to the presence of abundant collagen and elastin fibers | ||||
| stratum basale | deepest layer of the epidermis, made of epidermal stem cells | ||||
| stratum corneum | most superficial layer of the epidermis | ||||
| stratum granulosum | layer of the epidermis superficial to the stratum spinosum | ||||
| stratum lucidum | layer of the epidermis between the stratum granulosum and stratum corneum, found only in thick skin covering the palms, soles of the feet, and digits | ||||
| stratum spinosum | layer of the epidermis superficial to the stratum basale, characterized by the presence of desmosomes | ||||
| vitiligo | skin condition in which melanocytes in certain areas lose the ability to produce melanin, possibly due an autoimmune reaction that leads to loss of color in patches | ||||
| anagen | active phase of the hair growth cycle | ||||
| apocrine sweat gland | type of sweat gland that is associated with hair follicles in the armpits and genital regions | ||||
| arrector pili | smooth muscle that is activated in response to external stimuli that pull on hair follicles and make the hair “stand up” | ||||
| catagen | transitional phase marking the end of the anagen phase of the hair growth cycle | ||||
| cortex | in hair, the second or middle layer of keratinocytes originating from the hair matrix, as seen in a cross-section of the hair bulb | ||||
| cuticle | in hair, the outermost layer of keratinocytes originating from the hair matrix, as seen in a cross-section of the hair bulb | ||||
| eccrine sweat gland | type of sweat gland that is common throughout the skin surface; it produces a hypotonic sweat for thermoregulation | ||||
| eponychium | nail fold that meets the proximal end of the nail body, also called the cuticle | ||||
| external root sheath | outer layer of the hair follicle that is an extension of the epidermis, which encloses the hair root | ||||
| glassy membrane | layer of connective tissue that surrounds the base of the hair follicle, connecting it to the dermis | ||||
| hair | keratinous filament growing out of the epidermis | ||||
| hair bulb | structure at the base of the hair root that surrounds the dermal papilla | ||||
| hair follicle | cavity or sac from which hair originates | ||||
| hair matrix | layer of basal cells from which a strand of hair grows | ||||
| hair papilla | mass of connective tissue, blood capillaries, and nerve endings at the base of the hair follicle | ||||
| hair root | part of hair that is below the epidermis anchored to the follicle | ||||
| hair shaft | part of hair that is above the epidermis but is not anchored to the follicle | ||||
| hyponychium | thickened layer of stratum corneum that lies below the free edge of the nail | ||||
| internal root sheath | innermost layer of keratinocytes in the hair follicle that surround the hair root up to the hair shaft | ||||
| lunula | basal part of the nail body that consists of a crescent-shaped layer of thick epithelium | ||||
| medulla | in hair, the innermost layer of keratinocytes originating from the hair matrix | ||||
| nail bed | layer of epidermis upon which the nail body forms | ||||
| nail body | main keratinous plate that forms the nail | ||||
| nail cuticle | fold of epithelium that extends over the nail bed, also called the eponychium | ||||
| nail fold | fold of epithelium at that extend over the sides of the nail body, holding it in place | ||||
| nail root | part of the nail that is lodged deep in the epidermis from which the nail grows | ||||
| sebaceous gland | type of oil gland found in the dermis all over the body and helps to lubricate and waterproof the skin and hair by secreting sebum | ||||
| sebum | oily substance that is composed of a mixture of lipids that lubricates the skin and hair | ||||
| sudoriferous gland | sweat gland | ||||
| telogen | resting phase of the hair growth cycle initiated with catagen and terminated by the beginning of a new anagen phase of hair growth | ||||
| acne | skin condition due to infected sebaceous glands | ||||
| basal cell carcinoma | cancer that originates from basal cells in the epidermis of the skin | ||||
| bedsore | sore on the skin that develops when regions of the body start necrotizing due to constant pressure and lack of blood supply; also called decubitis ulcers | ||||
| callus | thickened area of skin that arises due to constant abrasion | ||||
| corn | type of callus that is named for its shape and the elliptical motion of the abrasive force | ||||
| eczema | skin condition due to an allergic reaction, which resembles a rash | ||||
| first-degree burn | superficial burn that injures only the epidermis | ||||
| fourth-degree burn | burn in which full thickness of the skin and underlying muscle and bone is damaged | ||||
| keloid | type of scar that has layers raised above the skin surface | ||||
| melanoma | type of skin cancer that originates from the melanocytes of the skin | ||||
| metastasis | spread of cancer cells from a source to other parts of the body | ||||
| scar | collagen-rich skin formed after the process of wound healing that is different from normal skin | ||||
| second-degree burn | partial-thickness burn that injures the epidermis and a portion of the dermis | ||||
| squamous cell carcinoma | type of skin cancer that originates from the stratum spinosum of the epidermis | ||||
| stretch mark | mark formed on the skin due to a sudden growth spurt and expansion of the dermis beyond its elastic limits | ||||
| third-degree burn | burn that penetrates and destroys the full thickness of the skin (epidermis and dermis) | ||||
| bone | hard, dense connective tissue that forms the structural elements of the skeleton | ||||
| cartilage | semi-rigid connective tissue found on the skeleton in areas where flexibility and smooth surfaces support movement | ||||
| hematopoiesis | production of blood cells, which occurs in the red marrow of the bones | ||||
| orthopedist | doctor who specializes in diagnosing and treating musculoskeletal disorders and injuries | ||||
| osseous tissue | bone tissue; a hard, dense connective tissue that forms the structural elements of the skeleton | ||||
| red marrow | connective tissue in the interior cavity of a bone where hematopoiesis takes place | ||||
| skeletal system | organ system composed of bones and cartilage that provides for movement, support, and protection | ||||
| yellow marrow | connective tissue in the interior cavity of a bone where fat is stored | ||||
| flat bone | thin and curved bone; serves as a point of attachment for muscles and protects internal organs | ||||
| irregular bone | bone of complex shape; protects internal organs from compressive forces | ||||
| long bone | cylinder-shaped bone that is longer than it is wide; functions as a lever | ||||
| sesamoid bone | small, round bone embedded in a tendon; protects the tendon from compressive forces | ||||
| short bone | cube-shaped bone that is approximately equal in length, width, and thickness; provides limited motion | ||||
| articular cartilage | thin layer of cartilage covering an epiphysis; reduces friction and acts as a shock absorber | ||||
| articulation | where two bone surfaces meet | ||||
| canaliculi | (singular = canaliculus) channels within the bone matrix that house one of an osteocyte’s many cytoplasmic extensions that it uses to communicate and receive nutrients | ||||
| central canal | longitudinal channel in the center of each osteon; contains blood vessels, nerves, and lymphatic vessels; also known as the Haversian canal | ||||
| compact bone | dense osseous tissue that can withstand compressive forces | ||||
| diaphysis | tubular shaft that runs between the proximal and distal ends of a long bone | ||||
| diploë | layer of spongy bone, that is sandwiched between two the layers of compact bone found in flat bones | ||||
| endosteum | delicate membranous lining of a bone’s medullary cavity | ||||
| epiphyseal plate | (also, growth plate) sheet of hyaline cartilage in the metaphysis of an immature bone; replaced by bone tissue as the organ grows in length | ||||
| epiphysis | wide section at each end of a long bone; filled with spongy bone and red marrow | ||||
| hole | opening or depression in a bone | ||||
| lacunae | (singular = lacuna) spaces in a bone that house an osteocyte | ||||
| medullary cavity | hollow region of the diaphysis; filled with yellow marrow | ||||
| nutrient foramen | small opening in the middle of the external surface of the diaphysis, through which an artery enters the bone to provide nourishment | ||||
| osteoblast | cell responsible for forming new bone | ||||
| osteoclast | cell responsible for resorbing bone | ||||
| osteocyte | primary cell in mature bone; responsible for maintaining the matrix | ||||
| osteogenic cell | undifferentiated cell with high mitotic activity; the only bone cells that divide; they differentiate and develop into osteoblasts | ||||
| osteon | (also, Haversian system) basic structural unit of compact bone; made of concentric layers of calcified matrix | ||||
| perforating canal | (also, Volkmann’s canal) channel that branches off from the central canal and houses vessels and nerves that extend to the periosteum and endosteum | ||||
| periosteum | fibrous membrane covering the outer surface of bone and continuous with ligaments | ||||
| projection | bone markings where part of the surface sticks out above the rest of the surface, where tendons and ligaments attach | ||||
| spongy bone | (also, cancellous bone) trabeculated osseous tissue that supports shifts in weight distribution | ||||
| trabeculae | (singular = trabecula) spikes or sections of the lattice-like matrix in spongy bone | ||||
| endochondral ossification | process in which bone forms by replacing hyaline cartilage | ||||
| epiphyseal line | completely ossified remnant of the epiphyseal plate | ||||
| intramembranous ossification | process by which bone forms directly from mesenchymal tissue | ||||
| modeling | process, during bone growth, by which bone is resorbed on one surface of a bone and deposited on another | ||||
| ossification | (also, osteogenesis) bone formation | ||||
| ossification center | cluster of osteoblasts found in the early stages of intramembranous ossification | ||||
| osteoid | uncalcified bone matrix secreted by osteoblasts | ||||
| perichondrium | membrane that covers cartilage | ||||
| primary ossification center | region, deep in the periosteal collar, where bone development starts during endochondral ossification | ||||
| proliferative zone | region of the epiphyseal plate that makes new chondrocytes to replace those that die at the diaphyseal end of the plate and contributes to longitudinal growth of the epiphyseal plate | ||||
| remodeling | process by which osteoclasts resorb old or damaged bone at the same time as and on the same surface where osteoblasts form new bone to replace that which is resorbed | ||||
| reserve zone | region of the epiphyseal plate that anchors the plate to the osseous tissue of the epiphysis | ||||
| secondary ossification center | region of bone development in the epiphyses | ||||
| zone of calcified matrix | region of the epiphyseal plate closest to the diaphyseal end; functions to connect the epiphyseal plate to the diaphysis | ||||
| zone of maturation and hypertrophy | region of the epiphyseal plate where chondrocytes from the proliferative zone grow and mature and contribute to the longitudinal growth of the epiphyseal plate | ||||
| closed reduction | manual manipulation of a broken bone to set it into its natural position without surgery | ||||
| external callus | collar of hyaline cartilage and bone that forms around the outside of a fracture | ||||
| fracture | broken bone | ||||
| fracture hematoma | blood clot that forms at the site of a broken bone | ||||
| internal callus | fibrocartilaginous matrix, in the endosteal region, between the two ends of a broken bone | ||||
| open reduction | surgical exposure of a bone to reset a fracture | ||||
| osteoporosis | disease characterized by a decrease in bone mass; occurs when the rate of bone resorption exceeds the rate of bone formation, a common occurrence as the body ages | ||||
| appendicular skeleton | all bones of the upper and lower limbs, plus the girdle bones that attach each limb to the axial skeleton | ||||
| axial skeleton | central, vertical axis of the body, including the skull, vertebral column, and thoracic cage | ||||
| coccyx | small bone located at inferior end of the adult vertebral column that is formed by the fusion of four coccygeal vertebrae; also referred to as the “tailbone” | ||||
| ear ossicles | three small bones located in the middle ear cavity that serve to transmit sound vibrations to the inner ear | ||||
| hyoid bone | small, U-shaped bone located in upper neck that does not contact any other bone | ||||
| ribs | thin, curved bones of the chest wall | ||||
| sacrum | single bone located near the inferior end of the adult vertebral column that is formed by the fusion of five sacral vertebrae; forms the posterior portion of the pelvis | ||||
| skeleton | bones of the body | ||||
| skull | bony structure that forms the head, face, and jaws, and protects the brain; consists of 22 bones | ||||
| sternum | flattened bone located at the center of the anterior chest | ||||
| thoracic cage | consists of 12 pairs of ribs and sternum | ||||
| vertebra | individual bone in the neck and back regions of the vertebral column | ||||
| vertebral column | entire sequence of bones that extend from the skull to the tailbone | ||||
| alveolar process of the mandible | upper border of mandibular body that contains the lower teeth | ||||
| alveolar process of the maxilla | curved, inferior margin of the maxilla that supports and anchors the upper teeth | ||||
| angle of the mandible | rounded corner located at outside margin of the body and ramus junction | ||||
| anterior cranial fossa | shallowest and most anterior cranial fossa of the cranial base that extends from the frontal bone to the lesser wing of the sphenoid bone | ||||
| articular tubercle | smooth ridge located on the inferior skull, immediately anterior to the mandibular fossa | ||||
| brain case | portion of the skull that contains and protects the brain, consisting of the eight bones that form the cranial base and rounded upper skull | ||||
| calvaria | (also, skullcap) rounded top of the skull | ||||
| carotid canal | zig-zag tunnel providing passage through the base of the skull for the internal carotid artery to the brain; begins anteromedial to the styloid process and terminates in the middle cranial cavity, near the posterior-lateral base of the sella turcica | ||||
| condylar process of the mandible | thickened upward projection from posterior margin of mandibular ramus | ||||
| condyle | oval-shaped process located at the top of the condylar process of the mandible | ||||
| coronal suture | joint that unites the frontal bone to the right and left parietal bones across the top of the skull | ||||
| coronoid process of the mandible | flattened upward projection from the anterior margin of the mandibular ramus | ||||
| cranial cavity | interior space of the skull that houses the brain | ||||
| cranium | skull | ||||
| cribriform plate | small, flattened areas with numerous small openings, located to either side of the midline in the floor of the anterior cranial fossa; formed by the ethmoid bone | ||||
| crista galli | small upward projection located at the midline in the floor of the anterior cranial fossa; formed by the ethmoid bone | ||||
| ethmoid air cell | one of several small, air-filled spaces located within the lateral sides of the ethmoid bone, between the orbit and upper nasal cavity | ||||
| ethmoid bone | unpaired bone that forms the roof and upper, lateral walls of the nasal cavity, portions of the floor of the anterior cranial fossa and medial wall of orbit, and the upper portion of the nasal septum | ||||
| external acoustic meatus | ear canal opening located on the lateral side of the skull | ||||
| external occipital protuberance | small bump located at the midline on the posterior skull | ||||
| facial bones | fourteen bones that support the facial structures and form the upper and lower jaws and the hard palate | ||||
| foramen lacerum | irregular opening in the base of the skull, located inferior to the exit of carotid canal | ||||
| foramen magnum | large opening in the occipital bone of the skull through which the spinal cord emerges and the vertebral arteries enter the cranium | ||||
| foramen ovale of the middle cranial fossa | oval-shaped opening in the floor of the middle cranial fossa | ||||
| foramen rotundum | round opening in the floor of the middle cranial fossa, located between the superior orbital fissure and foramen ovale | ||||
| foramen spinosum | small opening in the floor of the middle cranial fossa, located lateral to the foramen ovale | ||||
| frontal bone | unpaired bone that forms forehead, roof of orbit, and floor of anterior cranial fossa | ||||
| frontal sinus | air-filled space within the frontal bone; most anterior of the paranasal sinuses | ||||
| glabella | slight depression of frontal bone, located at the midline between the eyebrows | ||||
| greater wings of sphenoid bone | lateral projections of the sphenoid bone that form the anterior wall of the middle cranial fossa and an area of the lateral skull | ||||
| hard palate | bony structure that forms the roof of the mouth and floor of the nasal cavity, formed by the palatine process of the maxillary bones and the horizontal plate of the palatine bones | ||||
| horizontal plate | medial extension from the palatine bone that forms the posterior quarter of the hard palate | ||||
| hypoglossal canal | paired openings that pass anteriorly from the anterior-lateral margins of the foramen magnum deep to the occipital condyles | ||||
| hypophyseal (pituitary) fossa | shallow depression on top of the sella turcica that houses the pituitary (hypophyseal) gland | ||||
| inferior nasal concha | one of the paired bones that project from the lateral walls of the nasal cavity to form the largest and most inferior of the nasal conchae | ||||
| infraorbital foramen | opening located on anterior skull, below the orbit | ||||
| infratemporal fossa | space on lateral side of skull, below the level of the zygomatic arch and deep (medial) to the ramus of the mandible | ||||
| internal acoustic meatus | opening into petrous ridge, located on the lateral wall of the posterior cranial fossa | ||||
| jugular foramen | irregularly shaped opening located in the lateral floor of the posterior cranial cavity | ||||
| lacrimal bone | paired bones that contribute to the anterior-medial wall of each orbit | ||||
| lacrimal fossa | shallow depression in the anterior-medial wall of the orbit, formed by the lacrimal bone that gives rise to the nasolacrimal canal | ||||
| lambdoid suture | inverted V-shaped joint that unites the occipital bone to the right and left parietal bones on the posterior skull | ||||
| lateral pterygoid plate | paired, flattened bony projections of the sphenoid bone located on the inferior skull, lateral to the medial pterygoid plate | ||||
| lesser wings of the sphenoid bone | lateral extensions of the sphenoid bone that form the bony lip separating the anterior and middle cranial fossae | ||||
| lingula | small flap of bone located on the inner (medial) surface of mandibular ramus, next to the mandibular foramen | ||||
| mandible | unpaired bone that forms the lower jaw bone; the only moveable bone of the skull | ||||
| mandibular foramen | opening located on the inner (medial) surface of the mandibular ramus | ||||
| mandibular fossa | oval depression located on the inferior surface of the skull | ||||
| mandibular notch | large U-shaped notch located between the condylar process and coronoid process of the mandible | ||||
| mastoid process | large bony prominence on the inferior, lateral skull, just behind the earlobe | ||||
| maxillary bone | (also, maxilla) paired bones that form the upper jaw and anterior portion of the hard palate | ||||
| maxillary sinus | air-filled space located with each maxillary bone; largest of the paranasal sinuses | ||||
| medial pterygoid plate | paired, flattened bony projections of the sphenoid bone located on the inferior skull medial to the lateral pterygoid plate; form the posterior portion of the nasal cavity lateral wall | ||||
| mental foramen | opening located on the anterior-lateral side of the mandibular body | ||||
| mental protuberance | inferior margin of anterior mandible that forms the chin | ||||
| middle cranial fossa | centrally located cranial fossa that extends from the lesser wings of the sphenoid bone to the petrous ridge | ||||
| middle nasal concha | nasal concha formed by the ethmoid bone that is located between the superior and inferior conchae | ||||
| mylohyoid line | bony ridge located along the inner (medial) surface of the mandibular body | ||||
| nasal bone | paired bones that form the base of the nose | ||||
| nasal cavity | opening through skull for passage of air | ||||
| nasal conchae | curved bony plates that project from the lateral walls of the nasal cavity; include the superior and middle nasal conchae, which are parts of the ethmoid bone, and the independent inferior nasal conchae bone | ||||
| nasal septum | flat, midline structure that divides the nasal cavity into halves, formed by the perpendicular plate of the ethmoid bone, vomer bone, and septal cartilage | ||||
| nasolacrimal canal | passage for drainage of tears that extends downward from the medial-anterior orbit to the nasal cavity, terminating behind the inferior nasal conchae | ||||
| occipital bone | unpaired bone that forms the posterior portions of the brain case and base of the skull | ||||
| occipital condyle | paired, oval-shaped bony knobs located on the inferior skull, to either side of the foramen magnum | ||||
| optic canal | opening spanning between middle cranial fossa and posterior orbit | ||||
| orbit | bony socket that contains the eyeball and associated muscles | ||||
| palatine bone | paired bones that form the posterior quarter of the hard palate and a small area in floor of the orbit | ||||
| palatine process | medial projection from the maxilla bone that forms the anterior three quarters of the hard palate | ||||
| paranasal sinuses | cavities within the skull that are connected to the conchae that serve to warm and humidify incoming air, produce mucus, and lighten the weight of the skull; consist of frontal, maxillary, sphenoidal, and ethmoidal sinuses | ||||
| parietal bone | paired bones that form the upper, lateral sides of the skull | ||||
| perpendicular plate of the ethmoid bone | downward, midline extension of the ethmoid bone that forms the superior portion of the nasal septum | ||||
| petrous ridge | petrous portion of the temporal bone that forms a large, triangular ridge in the floor of the cranial cavity, separating the middle and posterior cranial fossae; houses the middle and inner ear structures | ||||
| posterior cranial fossa | deepest and most posterior cranial fossa; extends from the petrous ridge to the occipital bone | ||||
| pterion | H-shaped suture junction region that unites the frontal, parietal, temporal, and sphenoid bones on the lateral side of the skull | ||||
| ramus of the mandible | vertical portion of the mandible | ||||
| sagittal suture | joint that unites the right and left parietal bones at the midline along the top of the skull | ||||
| sella turcica | elevated area of sphenoid bone located at midline of the middle cranial fossa | ||||
| septal cartilage | flat cartilage structure that forms the anterior portion of the nasal septum | ||||
| sphenoid bone | unpaired bone that forms the central base of skull | ||||
| sphenoid sinus | air-filled space located within the sphenoid bone; most posterior of the paranasal sinuses | ||||
| squamous suture | joint that unites the parietal bone to the squamous portion of the temporal bone on the lateral side of the skull | ||||
| styloid process | downward projecting, elongated bony process located on the inferior aspect of the skull | ||||
| stylomastoid foramen | opening located on inferior skull, between the styloid process and mastoid process | ||||
| superior nasal concha | smallest and most superiorly located of the nasal conchae; formed by the ethmoid bone | ||||
| superior nuchal line | paired bony lines on the posterior skull that extend laterally from the external occipital protuberance | ||||
| superior orbital fissure | irregularly shaped opening between the middle cranial fossa and the posterior orbit | ||||
| supraorbital foramen | opening located on anterior skull, at the superior margin of the orbit | ||||
| supraorbital margin | superior margin of the orbit | ||||
| suture | junction line at which adjacent bones of the skull are united by fibrous connective tissue | ||||
| temporal bone | paired bones that form the lateral, inferior portions of the skull, with squamous, mastoid, and petrous portions | ||||
| temporal fossa | shallow space on the lateral side of the skull, above the level of the zygomatic arch | ||||
| temporal process of the zygomatic bone | short extension from the zygomatic bone that forms the anterior portion of the zygomatic arch | ||||
| vomer bone | unpaired bone that forms the inferior and posterior portions of the nasal septum | ||||
| zygomatic arch | elongated, free-standing arch on the lateral skull, formed anteriorly by the temporal process of the zygomatic bone and posteriorly by the zygomatic process of the temporal bone | ||||
| zygomatic bone | cheekbone; paired bones that contribute to the lateral orbit and anterior zygomatic arch | ||||
| zygomatic process of the temporal bone | extension from the temporal bone that forms the posterior portion of the zygomatic arch | ||||
| anterior arch | anterior portion of the ring-like C1 (atlas) vertebra | ||||
| anterior longitudinal ligament | ligament that runs the length of the vertebral column, uniting the anterior aspects of the vertebral bodies | ||||
| anterior (ventral) sacral foramen | one of the series of paired openings located on the anterior (ventral) side of the sacrum | ||||
| anulus fibrosus | tough, fibrous outer portion of an intervertebral disc, which is strongly anchored to the bodies of the adjacent vertebrae | ||||
| atlas | first cervical (C1) vertebra | ||||
| axis | second cervical (C2) vertebra | ||||
| cervical curve | posteriorly concave curvature of the cervical vertebral column region; a secondary curve of the vertebral column | ||||
| cervical vertebrae | seven vertebrae numbered as C1–C7 that are located in the neck region of the vertebral column | ||||
| costal facet | site on the lateral sides of a thoracic vertebra for articulation with the head of a rib | ||||
| dens | bony projection (odontoid process) that extends upward from the body of the C2 (axis) vertebra | ||||
| facet | small, flattened area on a bone for an articulation (joint) with another bone, or for muscle attachment | ||||
| inferior articular process | bony process that extends downward from the vertebral arch of a vertebra that articulates with the superior articular process of the next lower vertebra | ||||
| intervertebral disc | structure located between the bodies of adjacent vertebrae that strongly joins the vertebrae; provides padding, weight bearing ability, and enables vertebral column movements | ||||
| intervertebral foramen | opening located between adjacent vertebrae for exit of a spinal nerve | ||||
| kyphosis | (also, humpback or hunchback) excessive posterior curvature of the thoracic vertebral column region | ||||
| lamina | portion of the vertebral arch on each vertebra that extends between the transverse and spinous process | ||||
| lateral sacral crest | paired irregular ridges running down the lateral sides of the posterior sacrum that was formed by the fusion of the transverse processes from the five sacral vertebrae | ||||
| ligamentum flavum | series of short ligaments that unite the lamina of adjacent vertebrae | ||||
| lordosis | (also, swayback) excessive anterior curvature of the lumbar vertebral column region | ||||
| lumbar curve | posteriorly concave curvature of the lumbar vertebral column region; a secondary curve of the vertebral column | ||||
| lumbar vertebrae | five vertebrae numbered as L1–L5 that are located in lumbar region (lower back) of the vertebral column | ||||
| median sacral crest | irregular ridge running down the midline of the posterior sacrum that was formed from the fusion of the spinous processes of the five sacral vertebrae | ||||
| nuchal ligament | expanded portion of the supraspinous ligament within the posterior neck; interconnects the spinous processes of the cervical vertebrae and attaches to the base of the skull | ||||
| nucleus pulposus | gel-like central region of an intervertebral disc; provides for padding, weight-bearing, and movement between adjacent vertebrae | ||||
| pedicle | portion of the vertebral arch that extends from the vertebral body to the transverse process | ||||
| posterior arch | posterior portion of the ring-like C1 (atlas) vertebra | ||||
| posterior longitudinal ligament | ligament that runs the length of the vertebral column, uniting the posterior sides of the vertebral bodies | ||||
| posterior (dorsal) sacral foramen | one of the series of paired openings located on the posterior (dorsal) side of the sacrum | ||||
| primary curve | anteriorly concave curvatures of the thoracic and sacrococcygeal regions that are retained from the original fetal curvature of the vertebral column | ||||
| sacral canal | bony tunnel that runs through the sacrum | ||||
| sacral foramina | series of paired openings for nerve exit located on both the anterior (ventral) and posterior (dorsal) aspects of the sacrum | ||||
| sacral hiatus | inferior opening and termination of the sacral canal | ||||
| sacral promontory | anterior lip of the base (superior end) of the sacrum | ||||
| sacrococcygeal curve | anteriorly concave curvature formed by the sacrum and coccyx; a primary curve of the vertebral column | ||||
| scoliosis | abnormal lateral curvature of the vertebral column | ||||
| secondary curve | posteriorly concave curvatures of the cervical and lumbar regions of the vertebral column that develop after the time of birth | ||||
| spinous process | unpaired bony process that extends posteriorly from the vertebral arch of a vertebra | ||||
| superior articular process | bony process that extends upward from the vertebral arch of a vertebra that articulates with the inferior articular process of the next higher vertebra | ||||
| superior articular process of the sacrum | paired processes that extend upward from the sacrum to articulate (join) with the inferior articular processes from the L5 vertebra | ||||
| supraspinous ligament | ligament that interconnects the spinous processes of the thoracic and lumbar vertebrae | ||||
| thoracic curve | anteriorly concave curvature of the thoracic vertebral column region; a primary curve of the vertebral column | ||||
| thoracic vertebrae | twelve vertebrae numbered as T1–T12 that are located in the thoracic region (upper back) of the vertebral column | ||||
| transverse foramen | opening found only in the transverse processes of cervical vertebrae | ||||
| transverse process | paired bony processes that extends laterally from the vertebral arch of a vertebra | ||||
| vertebral arch | bony arch formed by the posterior portion of each vertebra that surrounds and protects the spinal cord | ||||
| vertebral (spinal) canal | bony passageway within the vertebral column for the spinal cord that is formed by the series of individual vertebral foramina | ||||
| vertebral foramen | opening associated with each vertebra defined by the vertebral arch that provides passage for the spinal cord | ||||
| angle of the rib | portion of rib with greatest curvature; together, the rib angles form the most posterior extent of the thoracic cage | ||||
| body of the rib | shaft portion of a rib | ||||
| clavicular notch | paired notches located on the superior-lateral sides of the sternal manubrium, for articulation with the clavicle | ||||
| costal cartilage | hyaline cartilage structure attached to the anterior end of each rib that provides for either direct or indirect attachment of most ribs to the sternum | ||||
| costal groove | shallow groove along the inferior margin of a rib that provides passage for blood vessels and a nerve | ||||
| false ribs | vertebrochondral ribs 8–12 whose costal cartilage either attaches indirectly to the sternum via the costal cartilage of the next higher rib or does not attach to the sternum at all | ||||
| floating ribs | vertebral ribs 11–12 that do not attach to the sternum or to the costal cartilage of another rib | ||||
| head of the rib | posterior end of a rib that articulates with the bodies of thoracic vertebrae | ||||
| jugular (suprasternal) notch | shallow notch located on superior surface of sternal manubrium | ||||
| manubrium | expanded, superior portion of the sternum | ||||
| neck of the rib | narrowed region of a rib, next to the rib head | ||||
| sternal angle | junction line between manubrium and body of the sternum and the site for attachment of the second rib to the sternum | ||||
| true ribs | vertebrosternal ribs 1–7 that attach via their costal cartilage directly to the sternum | ||||
| tubercle of the rib | small bump on the posterior side of a rib for articulation with the transverse process of a thoracic vertebra | ||||
| fontanelle | expanded area of fibrous connective tissue that separates the brain case bones of the skull prior to birth and during the first year after birth | ||||
| notochord | rod-like structure along dorsal side of the early embryo; largely disappears during later development but does contribute to formation of the intervertebral discs | ||||
| sclerotome | medial portion of a somite consisting of mesenchyme tissue that will give rise to bone, cartilage, and fibrous connective tissues | ||||
| somite | one of the paired, repeating blocks of tissue located on either side of the notochord in the early embryo | ||||
| acromial end of the clavicle | lateral end of the clavicle that articulates with the acromion of the scapula | ||||
| acromial process | acromion of the scapula | ||||
| acromioclavicular joint | articulation between the acromion of the scapula and the acromial end of the clavicle | ||||
| acromion | flattened bony process that extends laterally from the scapular spine to form the bony tip of the shoulder | ||||
| clavicle | collarbone; elongated bone that articulates with the manubrium of the sternum medially and the acromion of the scapula laterally | ||||
| coracoclavicular ligament | strong band of connective tissue that anchors the coracoid process of the scapula to the lateral clavicle; provides important indirect support for the acromioclavicular joint | ||||
| coracoid process | short, hook-like process that projects anteriorly and laterally from the superior margin of the scapula | ||||
| costoclavicular ligament | band of connective tissue that unites the medial clavicle with the first rib | ||||
| fossa | (plural = fossae) shallow depression on the surface of a bone | ||||
| glenohumeral joint | shoulder joint; formed by the articulation between the glenoid cavity of the scapula and the head of the humerus | ||||
| glenoid cavity | (also, glenoid fossa) shallow depression located on the lateral scapula, between the superior and lateral borders | ||||
| inferior angle of the scapula | inferior corner of the scapula located where the medial and lateral borders meet | ||||
| infraglenoid tubercle | small bump or roughened area located on the lateral border of the scapula, near the inferior margin of the glenoid cavity | ||||
| infraspinous fossa | broad depression located on the posterior scapula, inferior to the spine | ||||
| lateral border of the scapula | diagonally oriented lateral margin of the scapula | ||||
| medial border of the scapula | elongated, medial margin of the scapula | ||||
| pectoral girdle | shoulder girdle; the set of bones, consisting of the scapula and clavicle, which attaches each upper limb to the axial skeleton | ||||
| scapula | shoulder blade bone located on the posterior side of the shoulder | ||||
| spine of the scapula | prominent ridge passing mediolaterally across the upper portion of the posterior scapular surface | ||||
| sternal end of the clavicle | medial end of the clavicle that articulates with the manubrium of the sternum | ||||
| sternoclavicular joint | articulation between the manubrium of the sternum and the sternal end of the clavicle; forms the only bony attachment between the pectoral girdle of the upper limb and the axial skeleton | ||||
| subscapular fossa | broad depression located on the anterior (deep) surface of the scapula | ||||
| superior angle of the scapula | corner of the scapula between the superior and medial borders of the scapula | ||||
| superior border of the scapula | superior margin of the scapula | ||||
| supraglenoid tubercle | small bump located at the superior margin of the glenoid cavity | ||||
| suprascapular notch | small notch located along the superior border of the scapula, medial to the coracoid process | ||||
| supraspinous fossa | narrow depression located on the posterior scapula, superior to the spine | ||||
| anatomical neck | line on the humerus located around the outside margin of the humeral head | ||||
| arm | region of the upper limb located between the shoulder and elbow joints; contains the humerus bone | ||||
| bicipital groove | intertubercular groove; narrow groove located between the greater and lesser tubercles of the humerus | ||||
| capitate | from the lateral side, the third of the four distal carpal bones; articulates with the scaphoid and lunate proximally, the trapezoid laterally, the hamate medially, and primarily with the third metacarpal distally | ||||
| capitulum | knob-like bony structure located anteriorly on the lateral, distal end of the humerus | ||||
| carpal bone | one of the eight small bones that form the wrist and base of the hand; these are grouped as a proximal row consisting of (from lateral to medial) the scaphoid, lunate, triquetrum, and pisiform bones, and a distal row containing (from lateral to medial) the trapezium, trapezoid, capitate, and hamate bones | ||||
| carpal tunnel | passageway between the anterior forearm and hand formed by the carpal bones and flexor retinaculum | ||||
| carpometacarpal joint | articulation between one of the carpal bones in the distal row and a metacarpal bone of the hand | ||||
| coronoid fossa | depression on the anterior surface of the humerus above the trochlea; this space receives the coronoid process of the ulna when the elbow is maximally flexed | ||||
| coronoid process of the ulna | projecting bony lip located on the anterior, proximal ulna; forms the inferior margin of the trochlear notch | ||||
| deltoid tuberosity | roughened, V-shaped region located laterally on the mid-shaft of the humerus | ||||
| distal radioulnar joint | articulation between the head of the ulna and the ulnar notch of the radius | ||||
| elbow joint | joint located between the upper arm and forearm regions of the upper limb; formed by the articulations between the trochlea of the humerus and the trochlear notch of the ulna, and the capitulum of the humerus and the head of the radius | ||||
| flexor retinaculum | strong band of connective tissue at the anterior wrist that spans the top of the U-shaped grouping of the carpal bones to form the roof of the carpal tunnel | ||||
| forearm | region of the upper limb located between the elbow and wrist joints; contains the radius and ulna bones | ||||
| greater tubercle | enlarged prominence located on the lateral side of the proximal humerus | ||||
| hamate | from the lateral side, the fourth of the four distal carpal bones; articulates with the lunate and triquetrum proximally, the fourth and fifth metacarpals distally, and the capitate laterally | ||||
| hand | region of the upper limb distal to the wrist joint | ||||
| head of the humerus | smooth, rounded region on the medial side of the proximal humerus; articulates with the glenoid fossa of the scapula to form the glenohumeral (shoulder) joint | ||||
| head of the radius | disc-shaped structure that forms the proximal end of the radius; articulates with the capitulum of the humerus as part of the elbow joint, and with the radial notch of the ulna as part of the proximal radioulnar joint | ||||
| head of the ulna | small, rounded distal end of the ulna; articulates with the ulnar notch of the distal radius, forming the distal radioulnar joint | ||||
| hook of the hamate bone | bony extension located on the anterior side of the hamate carpal bone | ||||
| humerus | single bone of the upper arm | ||||
| interosseous border of the radius | narrow ridge located on the medial side of the radial shaft; for attachment of the interosseous membrane between the ulna and radius bones | ||||
| interosseous border of the ulna | narrow ridge located on the lateral side of the ulnar shaft; for attachment of the interosseous membrane between the ulna and radius | ||||
| interosseous membrane of the forearm | sheet of dense connective tissue that unites the radius and ulna bones | ||||
| interphalangeal joint | articulation between adjacent phalanx bones of the hand or foot digits | ||||
| intertubercular groove (sulcus) | bicipital groove; narrow groove located between the greater and lesser tubercles of the humerus | ||||
| lateral epicondyle of the humerus | small projection located on the lateral side of the distal humerus | ||||
| lateral supracondylar ridge | narrow, bony ridge located along the lateral side of the distal humerus, superior to the lateral epicondyle | ||||
| lesser tubercle | small, bony prominence located on anterior side of the proximal humerus | ||||
| lunate | from the lateral side, the second of the four proximal carpal bones; articulates with the radius proximally, the capitate and hamate distally, the scaphoid laterally, and the triquetrum medially | ||||
| medial epicondyle of the humerus | enlarged projection located on the medial side of the distal humerus | ||||
| metacarpal bone | one of the five long bones that form the palm of the hand; numbered 1–5, starting on the lateral (thumb) side of the hand | ||||
| metacarpophalangeal joint | articulation between the distal end of a metacarpal bone of the hand and a proximal phalanx bone of the thumb or a finger | ||||
| midcarpal joint | articulation between the proximal and distal rows of the carpal bones; contributes to movements of the hand at the wrist | ||||
| neck of the radius | narrowed region immediately distal to the head of the radius | ||||
| olecranon fossa | large depression located on the posterior side of the distal humerus; this space receives the olecranon process of the ulna when the elbow is fully extended | ||||
| olecranon process | expanded posterior and superior portions of the proximal ulna; forms the bony tip of the elbow | ||||
| phalanx bone of the hand | (plural = phalanges) one of the 14 bones that form the thumb and fingers; these include the proximal and distal phalanges of the thumb, and the proximal, middle, and distal phalanx bones of the fingers two through five | ||||
| pisiform | from the lateral side, the fourth of the four proximal carpal bones; articulates with the anterior surface of the triquetrum | ||||
| pollex | (also, thumb) digit 1 of the hand | ||||
| proximal radioulnar joint | articulation formed by the radial notch of the ulna and the head of the radius | ||||
| radial fossa | small depression located on the anterior humerus above the capitulum; this space receives the head of the radius when the elbow is maximally flexed | ||||
| radial notch of the ulna | small, smooth area on the lateral side of the proximal ulna; articulates with the head of the radius as part of the proximal radioulnar joint | ||||
| radial tuberosity | oval-shaped, roughened protuberance located on the medial side of the proximal radius | ||||
| radiocarpal joint | wrist joint, located between the forearm and hand regions of the upper limb; articulation formed proximally by the distal end of the radius and the fibrocartilaginous pad that unites the distal radius and ulna bone, and distally by the scaphoid, lunate, and triquetrum carpal bones | ||||
| radius | bone located on the lateral side of the forearm | ||||
| scaphoid | from the lateral side, the first of the four proximal carpal bones; articulates with the radius proximally, the trapezoid, trapezium, and capitate distally, and the lunate medially | ||||
| shaft of the humerus | narrow, elongated, central region of the humerus | ||||
| shaft of the radius | narrow, elongated, central region of the radius | ||||
| shaft of the ulna | narrow, elongated, central region of the ulna | ||||
| styloid process of the radius | pointed projection located on the lateral end of the distal radius | ||||
| styloid process of the ulna | short, bony projection located on the medial end of the distal ulna | ||||
| surgical neck | region of the humerus where the expanded, proximal end joins with the narrower shaft | ||||
| trapezium | from the lateral side, the first of the four distal carpal bones; articulates with the scaphoid proximally, the first and second metacarpals distally, and the trapezoid medially | ||||
| trapezoid | from the lateral side, the second of the four distal carpal bones; articulates with the scaphoid proximally, the second metacarpal distally, the trapezium laterally, and the capitate medially | ||||
| triquetrum | from the lateral side, the third of the four proximal carpal bones; articulates with the lunate laterally, the hamate distally, and has a facet for the pisiform | ||||
| trochlea | pulley-shaped region located medially at the distal end of the humerus; articulates at the elbow with the trochlear notch of the ulna | ||||
| trochlear notch | large, C-shaped depression located on the anterior side of the proximal ulna; articulates at the elbow with the trochlea of the humerus | ||||
| ulna | bone located on the medial side of the forearm | ||||
| ulnar notch of the radius | shallow, smooth area located on the medial side of the distal radius; articulates with the head of the ulna at the distal radioulnar joint | ||||
| ulnar tuberosity | roughened area located on the anterior, proximal ulna inferior to the coronoid process | ||||
| acetabulum | large, cup-shaped cavity located on the lateral side of the hip bone; formed by the junction of the ilium, pubis, and ischium portions of the hip bone | ||||
| anterior inferior iliac spine | small, bony projection located on the anterior margin of the ilium, below the anterior superior iliac spine | ||||
| anterior sacroiliac ligament | strong ligament between the sacrum and the ilium portions of the hip bone that supports the anterior side of the sacroiliac joint | ||||
| anterior superior iliac spine | rounded, anterior end of the iliac crest | ||||
| arcuate line of the ilium | smooth ridge located at the inferior margin of the iliac fossa; forms the lateral portion of the pelvic brim | ||||
| auricular surface of the ilium | roughened area located on the posterior, medial side of the ilium of the hip bone; articulates with the auricular surface of the sacrum to form the sacroiliac joint | ||||
| coxal bone | hip bone | ||||
| greater pelvis | (also, greater pelvic cavity or false pelvis) broad space above the pelvic brim defined laterally by the fan-like portion of the upper ilium | ||||
| greater sciatic foramen | pelvic opening formed by the greater sciatic notch of the hip bone, the sacrum, and the sacrospinous ligament | ||||
| greater sciatic notch | large, U-shaped indentation located on the posterior margin of the ilium, superior to the ischial spine | ||||
| hip bone | coxal bone; single bone that forms the pelvic girdle; consists of three areas, the ilium, ischium, and pubis | ||||
| iliac crest | curved, superior margin of the ilium | ||||
| iliac fossa | shallow depression found on the anterior and medial surfaces of the upper ilium | ||||
| ilium | superior portion of the hip bone | ||||
| inferior pubic ramus | narrow segment of bone that passes inferiorly and laterally from the pubic body; joins with the ischial ramus to form the ischiopubic ramus | ||||
| ischial ramus | bony extension projecting anteriorly and superiorly from the ischial tuberosity; joins with the inferior pubic ramus to form the ischiopubic ramus | ||||
| ischial spine | pointed, bony projection from the posterior margin of the ischium that separates the greater sciatic notch and lesser sciatic notch | ||||
| ischial tuberosity | large, roughened protuberance that forms the posteroinferior portion of the hip bone; weight-bearing region of the pelvis when sitting | ||||
| ischiopubic ramus | narrow extension of bone that connects the ischial tuberosity to the pubic body; formed by the junction of the ischial ramus and inferior pubic ramus | ||||
| ischium | posteroinferior portion of the hip bone | ||||
| lesser pelvis | (also, lesser pelvic cavity or true pelvis) narrow space located within the pelvis, defined superiorly by the pelvic brim (pelvic inlet) and inferiorly by the pelvic outlet | ||||
| lesser sciatic foramen | pelvic opening formed by the lesser sciatic notch of the hip bone, the sacrospinous ligament, and the sacrotuberous ligament | ||||
| lesser sciatic notch | shallow indentation along the posterior margin of the ischium, inferior to the ischial spine | ||||
| obturator foramen | large opening located in the anterior hip bone, between the pubis and ischium regions | ||||
| pectineal line | narrow ridge located on the superior surface of the superior pubic ramus | ||||
| pelvic brim | pelvic inlet; the dividing line between the greater and lesser pelvic regions; formed by the superior margin of the pubic symphysis, the pectineal lines of each pubis, the arcuate lines of each ilium, and the sacral promontory | ||||
| pelvic girdle | hip girdle; consists of a single hip bone, which attaches a lower limb to the sacrum of the axial skeleton | ||||
| pelvic inlet | pelvic brim | ||||
| pelvic outlet | inferior opening of the lesser pelvis; formed by the inferior margin of the pubic symphysis, right and left ischiopubic rami and sacrotuberous ligaments, and the tip of the coccyx | ||||
| pelvis | ring of bone consisting of the right and left hip bones, the sacrum, and the coccyx | ||||
| posterior inferior iliac spine | small, bony projection located at the inferior margin of the auricular surface on the posterior ilium | ||||
| posterior sacroiliac ligament | strong ligament spanning the sacrum and ilium of the hip bone that supports the posterior side of the sacroiliac joint | ||||
| posterior superior iliac spine | rounded, posterior end of the iliac crest | ||||
| pubic arch | bony structure formed by the pubic symphysis, and the bodies and inferior pubic rami of the right and left pubic bones | ||||
| pubic body | enlarged, medial portion of the pubis region of the hip bone | ||||
| pubic symphysis | joint formed by the articulation between the pubic bodies of the right and left hip bones | ||||
| pubic tubercle | small bump located on the superior aspect of the pubic body | ||||
| pubis | anterior portion of the hip bone | ||||
| sacroiliac joint | joint formed by the articulation between the auricular surfaces of the sacrum and ilium | ||||
| sacrospinous ligament | ligament that spans the sacrum to the ischial spine of the hip bone | ||||
| sacrotuberous ligament | ligament that spans the sacrum to the ischial tuberosity of the hip bone | ||||
| subpubic angle | inverted V-shape formed by the convergence of the right and left ischiopubic rami; this angle is greater than 80 degrees in females and less than 70 degrees in males | ||||
| superior pubic ramus | narrow segment of bone that passes laterally from the pubic body to join the ilium | ||||
| adductor tubercle | small, bony bump located on the superior aspect of the medial epicondyle of the femur | ||||
| ankle joint | joint that separates the leg and foot portions of the lower limb; formed by the articulations between the talus bone of the foot inferiorly, and the distal end of the tibia, medial malleolus of the tibia, and lateral malleolus of the fibula superiorly | ||||
| anterior border of the tibia | narrow, anterior margin of the tibia that extends inferiorly from the tibial tuberosity | ||||
| base of the metatarsal bone | expanded, proximal end of each metatarsal bone | ||||
| calcaneus | heel bone; posterior, inferior tarsal bone that forms the heel of the foot | ||||
| cuboid | tarsal bone that articulates posteriorly with the calcaneus bone, medially with the lateral cuneiform bone, and anteriorly with the fourth and fifth metatarsal bones | ||||
| distal tibiofibular joint | articulation between the distal fibula and the fibular notch of the tibia | ||||
| femur | thigh bone; the single bone of the thigh | ||||
| fibula | thin, non-weight-bearing bone found on the lateral side of the leg | ||||
| fibular notch | wide groove on the lateral side of the distal tibia for articulation with the fibula at the distal tibiofibular joint | ||||
| foot | portion of the lower limb located distal to the ankle joint | ||||
| fovea capitis | minor indentation on the head of the femur that serves as the site of attachment for the ligament to the head of the femur | ||||
| gluteal tuberosity | roughened area on the posterior side of the proximal femur, extending inferiorly from the base of the greater trochanter | ||||
| greater trochanter | large, bony expansion of the femur that projects superiorly from the base of the femoral neck | ||||
| hallux | big toe; digit 1 of the foot | ||||
| head of the femur | rounded, proximal end of the femur that articulates with the acetabulum of the hip bone to form the hip joint | ||||
| head of the fibula | small, knob-like, proximal end of the fibula; articulates with the inferior aspect of the lateral condyle of the tibia | ||||
| head of the metatarsal bone | expanded, distal end of each metatarsal bone | ||||
| hip joint | joint located at the proximal end of the lower limb; formed by the articulation between the acetabulum of the hip bone and the head of the femur | ||||
| intercondylar eminence | irregular elevation on the superior end of the tibia, between the articulating surfaces of the medial and lateral condyles | ||||
| intercondylar fossa | deep depression on the posterior side of the distal femur that separates the medial and lateral condyles | ||||
| intermediate cuneiform | middle of the three cuneiform tarsal bones; articulates posteriorly with the navicular bone, medially with the medial cuneiform bone, laterally with the lateral cuneiform bone, and anteriorly with the second metatarsal bone | ||||
| interosseous border of the fibula | small ridge running down the medial side of the fibular shaft; for attachment of the interosseous membrane between the fibula and tibia | ||||
| interosseous border of the tibia | small ridge running down the lateral side of the tibial shaft; for attachment of the interosseous membrane between the tibia and fibula | ||||
| interosseous membrane of the leg | sheet of dense connective tissue that unites the shafts of the tibia and fibula bones | ||||
| intertrochanteric crest | short, prominent ridge running between the greater and lesser trochanters on the posterior side of the proximal femur | ||||
| intertrochanteric line | small ridge running between the greater and lesser trochanters on the anterior side of the proximal femur | ||||
| knee joint | joint that separates the thigh and leg portions of the lower limb; formed by the articulations between the medial and lateral condyles of the femur, and the medial and lateral condyles of the tibia | ||||
| lateral condyle of the femur | smooth, articulating surface that forms the distal and posterior sides of the lateral expansion of the distal femur | ||||
| lateral condyle of the tibia | lateral, expanded region of the proximal tibia that includes the smooth surface that articulates with the lateral condyle of the femur as part of the knee joint | ||||
| lateral cuneiform | most lateral of the three cuneiform tarsal bones; articulates posteriorly with the navicular bone, medially with the intermediate cuneiform bone, laterally with the cuboid bone, and anteriorly with the third metatarsal bone | ||||
| lateral epicondyle of the femur | roughened area of the femur located on the lateral side of the lateral condyle | ||||
| lateral malleolus | expanded distal end of the fibula | ||||
| leg | portion of the lower limb located between the knee and ankle joints | ||||
| lesser trochanter | small, bony projection on the medial side of the proximal femur, at the base of the femoral neck | ||||
| ligament of the head of the femur | ligament that spans the acetabulum of the hip bone and the fovea capitis of the femoral head | ||||
| linea aspera | longitudinally running bony ridge located in the middle third of the posterior femur | ||||
| medial condyle of the femur | smooth, articulating surface that forms the distal and posterior sides of the medial expansion of the distal femur | ||||
| medial condyle of the tibia | medial, expanded region of the proximal tibia that includes the smooth surface that articulates with the medial condyle of the femur as part of the knee joint | ||||
| medial cuneiform | most medial of the three cuneiform tarsal bones; articulates posteriorly with the navicular bone, laterally with the intermediate cuneiform bone, and anteriorly with the first and second metatarsal bones | ||||
| medial epicondyle of the femur | roughened area of the distal femur located on the medial side of the medial condyle | ||||
| medial malleolus | bony expansion located on the medial side of the distal tibia | ||||
| metatarsal bone | one of the five elongated bones that forms the anterior half of the foot; numbered 1–5, starting on the medial side of the foot | ||||
| metatarsophalangeal joint | articulation between a metatarsal bone of the foot and the proximal phalanx bone of a toe | ||||
| navicular | tarsal bone that articulates posteriorly with the talus bone, laterally with the cuboid bone, and anteriorly with the medial, intermediate, and lateral cuneiform bones | ||||
| neck of the femur | narrowed region located inferior to the head of the femur | ||||
| patella | kneecap; the largest sesamoid bone of the body; articulates with the distal femur | ||||
| patellar surface | smooth groove located on the anterior side of the distal femur, between the medial and lateral condyles; site of articulation for the patella | ||||
| phalanx bone of the foot | (plural = phalanges) one of the 14 bones that form the toes; these include the proximal and distal phalanges of the big toe, and the proximal, middle, and distal phalanx bones of toes two through five | ||||
| proximal tibiofibular joint | articulation between the head of the fibula and the inferior aspect of the lateral condyle of the tibia | ||||
| shaft of the femur | cylindrically shaped region that forms the central portion of the femur | ||||
| shaft of the fibula | elongated, slender portion located between the expanded ends of the fibula | ||||
| shaft of the tibia | triangular-shaped, central portion of the tibia | ||||
| soleal line | small, diagonally running ridge located on the posterior side of the proximal tibia | ||||
| sustentaculum tali | bony ledge extending from the medial side of the calcaneus bone | ||||
| talus | tarsal bone that articulates superiorly with the tibia and fibula at the ankle joint; also articulates inferiorly with the calcaneus bone and anteriorly with the navicular bone | ||||
| tarsal bone | one of the seven bones that make up the posterior foot; includes the calcaneus, talus, navicular, cuboid, medial cuneiform, intermediate cuneiform, and lateral cuneiform bones | ||||
| thigh | portion of the lower limb located between the hip and knee joints | ||||
| tibia | shin bone; the large, weight-bearing bone located on the medial side of the leg | ||||
| apical ectodermal ridge | enlarged ridge of ectoderm at the distal end of a limb bud that stimulates growth and elongation of the limb | ||||
| amphiarthrosis | slightly mobile joint | ||||
| articulation | joint of the body | ||||
| biaxial joint | type of diarthrosis; a joint that allows for movements within two planes (two axes) | ||||
| cartilaginous joint | joint at which the bones are united by hyaline cartilage (synchondrosis) or fibrocartilage (symphysis) | ||||
| diarthrosis | freely mobile joint | ||||
| fibrous joint | joint where the articulating areas of the adjacent bones are connected by fibrous connective tissue | ||||
| joint | site at which two or more bones or bone and cartilage come together (articulate) | ||||
| joint cavity | space enclosed by the articular capsule of a synovial joint that is filled with synovial fluid and contains the articulating surfaces of the adjacent bones | ||||
| multiaxial joint | type of diarthrosis; a joint that allows for movements within three planes (three axes) | ||||
| synarthrosis | immobile or nearly immobile joint | ||||
| synovial joint | joint at which the articulating surfaces of the bones are located within a joint cavity formed by an articular capsule | ||||
| uniaxial joint | type of diarthrosis; joint that allows for motion within only one plane (one axis) | ||||
| fontanelles | expanded areas of fibrous connective tissue that separate the braincase bones of the skull prior to birth and during the first year after birth | ||||
| gomphosis | type of fibrous joint in which the root of a tooth is anchored into its bony jaw socket by strong periodontal ligaments | ||||
| interosseous membrane | wide sheet of fibrous connective tissue that fills the gap between two parallel bones, forming a syndesmosis; found between the radius and ulna of the forearm and between the tibia and fibula of the leg | ||||
| ligament | strong band of dense connective tissue spanning between bones | ||||
| periodontal ligament | band of dense connective tissue that anchors the root of a tooth into the bony jaw socket | ||||
| suture | fibrous joint that connects the bones of the skull (except the mandible); an immobile joint (synarthrosis) | ||||
| syndesmosis | type of fibrous joint in which two separated, parallel bones are connected by an interosseous membrane | ||||
| synostosis | site at which adjacent bones or bony components have fused together | ||||
| symphysis | type of cartilaginous joint where the bones are joined by fibrocartilage | ||||
| synchondrosis | type of cartilaginous joint where the bones are joined by hyaline cartilage | ||||
| articular capsule | connective tissue structure that encloses the joint cavity of a synovial joint | ||||
| articular cartilage | thin layer of hyaline cartilage that covers the articulating surfaces of bones at a synovial joint | ||||
| articular disc | meniscus; a fibrocartilage structure found between the bones of some synovial joints; provides padding or smooths movements between the bones; strongly unites the bones together | ||||
| ball-and-socket joint | synovial joint formed between the spherical end of one bone (the ball) that fits into the depression of a second bone (the socket); found at the hip and shoulder joints; functionally classified as a multiaxial joint | ||||
| bursa | connective tissue sac containing lubricating fluid that prevents friction between adjacent structures, such as skin and bone, tendons and bone, or between muscles | ||||
| condyloid joint | synovial joint in which the shallow depression at the end of one bone receives a rounded end from a second bone or a rounded structure formed by two bones; found at the metacarpophalangeal joints of the fingers or the radiocarpal joint of the wrist; functionally classified as a biaxial joint | ||||
| extrinsic ligament | ligament located outside of the articular capsule of a synovial joint | ||||
| hinge joint | synovial joint at which the convex surface of one bone articulates with the concave surface of a second bone; includes the elbow, knee, ankle, and interphalangeal joints; functionally classified as a uniaxial joint | ||||
| intracapsular ligament | ligament that is located within the articular capsule of a synovial joint | ||||
| intrinsic ligament | ligament that is fused to or incorporated into the wall of the articular capsule of a synovial joint | ||||
| meniscus | articular disc | ||||
| pivot joint | synovial joint at which the rounded portion of a bone rotates within a ring formed by a ligament and an articulating bone; functionally classified as uniaxial joint | ||||
| plane joint | synovial joint formed between the flattened articulating surfaces of adjacent bones; functionally classified as a multiaxial joint | ||||
| proximal radioulnar joint | articulation between head of radius and radial notch of ulna; uniaxial pivot joint that allows for rotation of radius during pronation/supination of forearm | ||||
| saddle joint | synovial joint in which the articulating ends of both bones are convex and concave in shape, such as at the first carpometacarpal joint at the base of the thumb; functionally classified as a biaxial joint | ||||
| subcutaneous bursa | bursa that prevents friction between skin and an underlying bone | ||||
| submuscular bursa | bursa that prevents friction between bone and a muscle or between adjacent muscles | ||||
| subtendinous bursa | bursa that prevents friction between bone and a muscle tendon | ||||
| synovial fluid | thick, lubricating fluid that fills the interior of a synovial joint | ||||
| synovial membrane | thin layer that lines the inner surface of the joint cavity at a synovial joint; produces the synovial fluid | ||||
| tendon | dense connective tissue structure that anchors a muscle to bone | ||||
| tendon sheath | connective tissue that surrounds a tendon at places where the tendon crosses a joint; contains a lubricating fluid to prevent friction and allow smooth movements of the tendon | ||||
| abduction | movement in the coronal plane that moves a limb laterally away from the body; spreading of the fingers | ||||
| adduction | movement in the coronal plane that moves a limb medially toward or across the midline of the body; bringing fingers together | ||||
| circumduction | circular motion of the arm, thigh, hand, thumb, or finger that is produced by the sequential combination of flexion, abduction, extension, and adduction | ||||
| depression | downward (inferior) motion of the scapula or mandible | ||||
| dorsiflexion | movement at the ankle that brings the top of the foot toward the anterior leg | ||||
| elevation | upward (superior) motion of the scapula or mandible | ||||
| eversion | foot movement involving the intertarsal joints of the foot in which the bottom of the foot is turned laterally, away from the midline | ||||
| extension | movement in the sagittal plane that increases the angle of a joint (straightens the joint); motion involving posterior bending of the vertebral column or returning to the upright position from a flexed position | ||||
| flexion | movement in the sagittal plane that decreases the angle of a joint (bends the joint); motion involving anterior bending of the vertebral column | ||||
| hyperextension | excessive extension of joint, beyond the normal range of movement | ||||
| hyperflexion | excessive flexion of joint, beyond the normal range of movement | ||||
| inferior rotation | movement of the scapula during upper limb adduction in which the glenoid cavity of the scapula moves in a downward direction as the medial end of the scapular spine moves in an upward direction | ||||
| inversion | foot movement involving the intertarsal joints of the foot in which the bottom of the foot is turned toward the midline | ||||
| lateral excursion | side-to-side movement of the mandible away from the midline, toward either the right or left side | ||||
| lateral flexion | bending of the neck or body toward the right or left side | ||||
| lateral (external) rotation | movement of the arm at the shoulder joint or the thigh at the hip joint that moves the anterior surface of the limb away from the midline of the body | ||||
| medial excursion | side-to-side movement that returns the mandible to the midline | ||||
| medial (internal) rotation | movement of the arm at the shoulder joint or the thigh at the hip joint that brings the anterior surface of the limb toward the midline of the body | ||||
| opposition | thumb movement that brings the tip of the thumb in contact with the tip of a finger | ||||
| plantar flexion | foot movement at the ankle in which the heel is lifted off of the ground | ||||
| pronated position | forearm position in which the palm faces backward | ||||
| pronation | forearm motion that moves the palm of the hand from the palm forward to the palm backward position | ||||
| protraction | anterior motion of the scapula or mandible | ||||
| reposition | movement of the thumb from opposition back to the anatomical position (next to index finger) | ||||
| retraction | posterior motion of the scapula or mandible | ||||
| rotation | movement of a bone around a central axis (atlantoaxial joint) or around its long axis (proximal radioulnar joint; shoulder or hip joint); twisting of the vertebral column resulting from the summation of small motions between adjacent vertebrae | ||||
| superior rotation | movement of the scapula during upper limb abduction in which the glenoid cavity of the scapula moves in an upward direction as the medial end of the scapular spine moves in a downward direction | ||||
| supinated position | forearm position in which the palm faces anteriorly (anatomical position) | ||||
| supination | forearm motion that moves the palm of the hand from the palm backward to the palm forward position | ||||
| acetabular labrum | lip of fibrocartilage that surrounds outer margin of the acetabulum on the hip bone | ||||
| annular ligament | intrinsic ligament of the elbow articular capsule that surrounds and supports the head of the radius at the proximal radioulnar joint | ||||
| anterior cruciate ligament | intracapsular ligament of the knee; extends from anterior, superior surface of the tibia to the inner aspect of the lateral condyle of the femur; resists hyperextension of knee | ||||
| anterior talofibular ligament | intrinsic ligament located on the lateral side of the ankle joint, between talus bone and lateral malleolus of fibula; supports talus at the talocrural joint and resists excess inversion of the foot | ||||
| atlantoaxial joint | series of three articulations between the atlas (C1) vertebra and the axis (C2) vertebra, consisting of the joints between the inferior articular processes of C1 and the superior articular processes of C2, and the articulation between the dens of C2 and the anterior arch of C1 | ||||
| atlanto-occipital joint | articulation between the occipital condyles of the skull and the superior articular processes of the atlas (C1 vertebra) | ||||
| calcaneofibular ligament | intrinsic ligament located on the lateral side of the ankle joint, between the calcaneus bone and lateral malleolus of the fibula; supports the talus bone at the ankle joint and resists excess inversion of the foot | ||||
| coracohumeral ligament | intrinsic ligament of the shoulder joint; runs from the coracoid process of the scapula to the anterior humerus | ||||
| deltoid ligament | broad intrinsic ligament located on the medial side of the ankle joint; supports the talus at the talocrural joint and resists excess eversion of the foot | ||||
| elbow joint | humeroulnar joint | ||||
| femoropatellar joint | portion of the knee joint consisting of the articulation between the distal femur and the patella | ||||
| fibular collateral ligament | extrinsic ligament of the knee joint that spans from the lateral epicondyle of the femur to the head of the fibula; resists hyperextension and rotation of the extended knee | ||||
| glenohumeral joint | shoulder joint; articulation between the glenoid cavity of the scapula and head of the humerus; multiaxial ball-and-socket joint that allows for flexion/extension, abduction/adduction, circumduction, and medial/lateral rotation of the humerus | ||||
| glenohumeral ligament | one of the three intrinsic ligaments of the shoulder joint that strengthen the anterior articular capsule | ||||
| glenoid labrum | lip of fibrocartilage located around the outside margin of the glenoid cavity of the scapula | ||||
| humeroradial joint | articulation between the capitulum of the humerus and head of the radius | ||||
| humeroulnar joint | articulation between the trochlea of humerus and the trochlear notch of the ulna; uniaxial hinge joint that allows for flexion/extension of the forearm | ||||
| iliofemoral ligament | intrinsic ligament spanning from the ilium of the hip bone to the femur, on the superior-anterior aspect of the hip joint | ||||
| ischiofemoral ligament | intrinsic ligament spanning from the ischium of the hip bone to the femur, on the posterior aspect of the hip joint | ||||
| lateral meniscus | C-shaped fibrocartilage articular disc located at the knee, between the lateral condyle of the femur and the lateral condyle of the tibia | ||||
| lateral tibiofemoral joint | portion of the knee consisting of the articulation between the lateral condyle of the tibia and the lateral condyle of the femur; allows for flexion/extension at the knee | ||||
| ligament of the head of the femur | intracapsular ligament that runs from the acetabulum of the hip bone to the head of the femur | ||||
| medial meniscus | C-shaped fibrocartilage articular disc located at the knee, between the medial condyle of the femur and medial condyle of the tibia | ||||
| medial tibiofemoral joint | portion of the knee consisting of the articulation between the medial condyle of the tibia and the medial condyle of the femur; allows for flexion/extension at the knee | ||||
| patellar ligament | ligament spanning from the patella to the anterior tibia; serves as the final attachment for the quadriceps femoris muscle | ||||
| posterior cruciate ligament | intracapsular ligament of the knee; extends from the posterior, superior surface of the tibia to the inner aspect of the medial condyle of the femur; prevents anterior displacement of the femur when the knee is flexed and weight bearing | ||||
| posterior talofibular ligament | intrinsic ligament located on the lateral side of the ankle joint, between the talus bone and lateral malleolus of the fibula; supports the talus at the talocrural joint and resists excess inversion of the foot | ||||
| pubofemoral ligament | intrinsic ligament spanning from the pubis of the hip bone to the femur, on the anterior-inferior aspect of the hip joint | ||||
| radial collateral ligament | intrinsic ligament on the lateral side of the elbow joint; runs from the lateral epicondyle of humerus to merge with the annular ligament | ||||
| rotator cuff | strong connective tissue structure formed by the fusion of four rotator cuff muscle tendons to the articular capsule of the shoulder joint; surrounds and supports superior, anterior, lateral, and posterior sides of the humeral head | ||||
| subacromial bursa | bursa that protects the supraspinatus muscle tendon and superior end of the humerus from rubbing against the acromion of the scapula | ||||
| subscapular bursa | bursa that prevents rubbing of the subscapularis muscle tendon against the scapula | ||||
| subtalar joint | articulation between the talus and calcaneus bones of the foot; allows motions that contribute to inversion/eversion of the foot | ||||
| talocrural joint | ankle joint; articulation between the talus bone of the foot and medial malleolus of the tibia, distal tibia, and lateral malleolus of the fibula; a uniaxial hinge joint that allows only for dorsiflexion and plantar flexion of the foot | ||||
| temporomandibular joint (TMJ) | articulation between the condyle of the mandible and the mandibular fossa and articular tubercle of the temporal bone of the skull; allows for depression/elevation (opening/closing of mouth), protraction/retraction, and side-to-side motions of the mandible | ||||
| tibial collateral ligament | extrinsic ligament of knee joint that spans from the medial epicondyle of the femur to the medial tibia; resists hyperextension and rotation of extended knee | ||||
| ulnar collateral ligament | intrinsic ligament on the medial side of the elbow joint; spans from the medial epicondyle of the humerus to the medial ulna | ||||
| zygapophysial joints | facet joints; plane joints between the superior and inferior articular processes of adjacent vertebrae that provide for only limited motions between the vertebrae | ||||
| cardiac muscle | striated muscle found in the heart; joined to one another at intercalated discs and under the regulation of pacemaker cells, which contract as one unit to pump blood through the circulatory system. Cardiac muscle is under involuntary control. | ||||
| contractility | ability to shorten (contract) forcibly | ||||
| elasticity | ability to stretch and rebound | ||||
| excitability | ability to undergo neural stimulation | ||||
| extensibility | ability to lengthen (extend) | ||||
| skeletal muscle | striated, multinucleated muscle that requires signaling from the nervous system to trigger contraction; most skeletal muscles are referred to as voluntary muscles that move bones and produce movement | ||||
| smooth muscle | nonstriated, mononucleated muscle in the skin that is associated with hair follicles; assists in moving materials in the walls of internal organs, blood vessels, and internal passageways | ||||
| acetylcholine (ACh) | neurotransmitter that binds at a motor end-plate to trigger depolarization | ||||
| actin | protein that makes up most of the thin myofilaments in a sarcomere muscle fiber | ||||
| action potential | change in voltage of a cell membrane in response to a stimulus that results in transmission of an electrical signal; unique to neurons and muscle fibers | ||||
| aponeurosis | broad, tendon-like sheet of connective tissue that attaches a skeletal muscle to another skeletal muscle or to a bone | ||||
| depolarize | to reduce the voltage difference between the inside and outside of a cell’s plasma membrane (the sarcolemma for a muscle fiber), making the inside less negative than at rest | ||||
| endomysium | loose, and well-hydrated connective tissue covering each muscle fiber in a skeletal muscle | ||||
| epimysium | outer layer of connective tissue around a skeletal muscle | ||||
| excitation-contraction coupling | sequence of events from motor neuron signaling to a skeletal muscle fiber to contraction of the fiber’s sarcomeres | ||||
| fascicle | bundle of muscle fibers within a skeletal muscle | ||||
| motor end-plate | sarcolemma of muscle fiber at the neuromuscular junction, with receptors for the neurotransmitter acetylcholine | ||||
| myofibril | long, cylindrical organelle that runs parallel within the muscle fiber and contains the sarcomeres | ||||
| myosin | protein that makes up most of the thick cylindrical myofilament within a sarcomere muscle fiber | ||||
| neuromuscular junction (NMJ) | synapse between the axon terminal of a motor neuron and the section of the membrane of a muscle fiber with receptors for the acetylcholine released by the terminal | ||||
| neurotransmitter | signaling chemical released by nerve terminals that bind to and activate receptors on target cells | ||||
| perimysium | connective tissue that bundles skeletal muscle fibers into fascicles within a skeletal muscle | ||||
| sarcomere | longitudinally, repeating functional unit of skeletal muscle, with all of the contractile and associated proteins involved in contraction | ||||
| sarcolemma | plasma membrane of a skeletal muscle fiber | ||||
| sarcoplasm | cytoplasm of a muscle cell | ||||
| sarcoplasmic reticulum (SR) | specialized smooth endoplasmic reticulum, which stores, releases, and retrieves Ca++ | ||||
| synaptic cleft | space between a nerve (axon) terminal and a motor end-plate | ||||
| T-tubule | projection of the sarcolemma into the interior of the cell | ||||
| thick filament | the thick myosin strands and their multiple heads projecting from the center of the sarcomere toward, but not all to way to, the Z-discs | ||||
| thin filament | thin strands of actin and its troponin-tropomyosin complex projecting from the Z-discs toward the center of the sarcomere | ||||
| triad | the grouping of one T-tubule and two terminal cisternae | ||||
| troponin | regulatory protein that binds to actin, tropomyosin, and calcium | ||||
| tropomyosin | regulatory protein that covers myosin-binding sites to prevent actin from binding to myosin | ||||
| voltage-gated sodium channels | membrane proteins that open sodium channels in response to a sufficient voltage change, and initiate and transmit the action potential as Na+ enters through the channel | ||||
| aerobic respiration | production of ATP in the presence of oxygen | ||||
| ATPase | enzyme that hydrolyzes ATP to ADP | ||||
| creatine phosphate | phosphagen used to store energy from ATP and transfer it to muscle | ||||
| glycolysis | anaerobic breakdown of glucose to ATP | ||||
| lactic acid | product of anaerobic glycolysis | ||||
| oxygen debt | amount of oxygen needed to compensate for ATP produced without oxygen during muscle contraction | ||||
| power stroke | action of myosin pulling actin inward (toward the M line) | ||||
| pyruvic acid | product of glycolysis that can be used in aerobic respiration or converted to lactic acid | ||||
| fast glycolytic (FG) | muscle fiber that primarily uses anaerobic glycolysis | ||||
| fast oxidative (FO) | intermediate muscle fiber that is between slow oxidative and fast glycolytic fibers | ||||
| slow oxidative (SO) | muscle fiber that primarily uses aerobic respiration | ||||
| abduct | move away from midline in the sagittal plane | ||||
| agonist | (also, prime mover) muscle whose contraction is responsible for producing a particular motion | ||||
| antagonist | muscle that opposes the action of an agonist | ||||
| belly | bulky central body of a muscle | ||||
| bipennate | pennate muscle that has fascicles that are located on both sides of the tendon | ||||
| circular | (also, sphincter) fascicles that are concentrically arranged around an opening | ||||
| convergent | fascicles that extend over a broad area and converge on a common attachment site | ||||
| fascicle | muscle fibers bundled by perimysium into a unit | ||||
| fixator | synergist that assists an agonist by preventing or reducing movement at another joint, thereby stabilizing the origin of the agonist | ||||
| flexion | movement that decreases the angle of a joint | ||||
| fusiform | muscle that has fascicles that are spindle-shaped to create large bellies | ||||
| insertion | end of a skeletal muscle that is attached to the structure (usually a bone) that is moved when the muscle contracts | ||||
| multipennate | pennate muscle that has a tendon branching within it | ||||
| origin | end of a skeletal muscle that is attached to another structure (usually a bone) in a fixed position | ||||
| parallel | fascicles that extend in the same direction as the long axis of the muscle | ||||
| pennate | fascicles that are arranged differently based on their angles to the tendon | ||||
| prime mover | (also, agonist) principle muscle involved in an action | ||||
| synergist | muscle whose contraction helps a prime mover in an action | ||||
| unipennate | pennate muscle that has fascicles located on one side of the tendon | ||||
| abductor | moves the bone away from the midline | ||||
| adductor | moves the bone toward the midline | ||||
| bi | two | ||||
| brevis | short | ||||
| extensor | muscle that increases the angle at the joint | ||||
| flexor | muscle that decreases the angle at the joint | ||||
| lateralis | to the outside | ||||
| longus | long | ||||
| maximus | largest | ||||
| medialis | to the inside | ||||
| medius | medium | ||||
| minimus | smallest | ||||
| oblique | at an angle | ||||
| rectus | straight | ||||
| tri | three | ||||
| anterior scalene | a muscle anterior to the middle scalene | ||||
| appendicular | of the arms and legs | ||||
| axial | of the trunk and head | ||||
| buccinator | muscle that compresses the cheek | ||||
| corrugator supercilii | prime mover of the eyebrows | ||||
| deglutition | swallowing | ||||
| digastric | muscle that has anterior and posterior bellies and elevates the hyoid bone and larynx when one swallows; it also depresses the mandible | ||||
| epicranial aponeurosis | (also, galea aponeurosis) flat broad tendon that connects the frontalis and occipitalis | ||||
| erector spinae group | large muscle mass of the back; primary extensor of the vertebral column | ||||
| extrinsic eye muscles | originate outside the eye and insert onto the outer surface of the white of the eye, and create eyeball movement | ||||
| frontalis | front part of the occipitofrontalis muscle | ||||
| genioglossus | muscle that originates on the mandible and allows the tongue to move downward and forward | ||||
| geniohyoid | muscle that depresses the mandible, and raises and pulls the hyoid bone anteriorly | ||||
| hyoglossus | muscle that originates on the hyoid bone to move the tongue downward and flatten it | ||||
| iliocostalis cervicis | muscle of the iliocostalis group associated with the cervical region | ||||
| iliocostalis group | laterally placed muscles of the erector spinae | ||||
| iliocostalis lumborum | muscle of the iliocostalis group associated with the lumbar region | ||||
| iliocostalis thoracis | muscle of the iliocostalis group associated with the thoracic region | ||||
| infrahyoid muscles | anterior neck muscles that are attached to, and inferior to the hyoid bone | ||||
| lateral pterygoid | muscle that moves the mandible from side to side | ||||
| longissimus capitis | muscle of the longissimus group associated with the head region | ||||
| longissimus cervicis | muscle of the longissimus group associated with the cervical region | ||||
| longissimus group | intermediately placed muscles of the erector spinae | ||||
| longissimus thoracis | muscle of the longissimus group associated with the thoracic region | ||||
| masseter | main muscle for chewing that elevates the mandible to close the mouth | ||||
| mastication | chewing | ||||
| medial pterygoid | muscle that moves the mandible from side to side | ||||
| middle scalene | longest scalene muscle, located between the anterior and posterior scalenes | ||||
| multifidus | muscle of the lumbar region that helps extend and laterally flex the vertebral column | ||||
| mylohyoid | muscle that lifts the hyoid bone and helps press the tongue to the top of the mouth | ||||
| occipitalis | posterior part of the occipitofrontalis muscle | ||||
| occipitofrontalis | muscle that makes up the scalp with a frontal belly and an occipital belly | ||||
| omohyoid | muscle that has superior and inferior bellies and depresses the hyoid bone | ||||
| orbicularis oculi | circular muscle that closes the eye | ||||
| orbicularis oris | circular muscle that moves the lips | ||||
| palatoglossus | muscle that originates on the soft palate to elevate the back of the tongue | ||||
| posterior scalene | smallest scalene muscle, located posterior to the middle scalene | ||||
| scalene muscles | flex, laterally flex, and rotate the head; contribute to deep inhalation | ||||
| segmental muscle group | interspinales and intertransversarii muscles that bring together the spinous and transverse processes of each consecutive vertebra | ||||
| semispinalis capitis | transversospinales muscle associated with the head region | ||||
| semispinalis cervicis | transversospinales muscle associated with the cervical region | ||||
| semispinalis thoracis | transversospinales muscle associated with the thoracic region | ||||
| spinalis capitis | muscle of the spinalis group associated with the head region | ||||
| spinalis cervicis | muscle of the spinalis group associated with the cervical region | ||||
| spinalis group | medially placed muscles of the erector spinae | ||||
| spinalis thoracis | muscle of the spinalis group associated with the thoracic region | ||||
| splenius | posterior neck muscles; includes the splenius capitis and splenius cervicis | ||||
| splenius capitis | neck muscle that inserts into the head region | ||||
| splenius cervicis | neck muscle that inserts into the cervical region | ||||
| sternocleidomastoid | major muscle that laterally flexes and rotates the head | ||||
| sternohyoid | muscle that depresses the hyoid bone | ||||
| sternothyroid | muscle that depresses the larynx’s thyroid cartilage | ||||
| styloglossus | muscle that originates on the styloid bone, and allows upward and backward motion of the tongue | ||||
| stylohyoid | muscle that elevates the hyoid bone posteriorly | ||||
| suprahyoid muscles | neck muscles that are superior to the hyoid bone | ||||
| temporalis | muscle that retracts the mandible | ||||
| thyrohyoid | muscle that depresses the hyoid bone and elevates the larynx’s thyroid cartilage | ||||
| transversospinales | muscles that originate at the transverse processes and insert at the spinous processes of the vertebrae | ||||
| anal triangle | posterior triangle of the perineum that includes the anus | ||||
| caval opening | opening in the diaphragm that allows the inferior vena cava to pass through; foramen for the vena cava | ||||
| compressor urethrae | deep perineal muscle in women | ||||
| deep transverse perineal | deep perineal muscle in men | ||||
| diaphragm | skeletal muscle that separates the thoracic and abdominal cavities and is dome-shaped at rest | ||||
| external intercostal | superficial intercostal muscles that raise the rib cage | ||||
| external oblique | superficial abdominal muscle with fascicles that extend inferiorly and medially | ||||
| iliococcygeus | muscle that makes up the levator ani along with the pubococcygeus | ||||
| innermost intercostal | the deepest intercostal muscles that draw the ribs together | ||||
| intercostal muscles | muscles that span the spaces between the ribs | ||||
| internal intercostal | muscles the intermediate intercostal muscles that draw the ribs together | ||||
| internal oblique | flat, intermediate abdominal muscle with fascicles that run perpendicular to those of the external oblique | ||||
| ischiococcygeus | muscle that assists the levator ani and pulls the coccyx anteriorly | ||||
| levator ani | pelvic muscle that resists intra-abdominal pressure and supports the pelvic viscera | ||||
| linea alba | white, fibrous band that runs along the midline of the trunk | ||||
| pelvic diaphragm | muscular sheet that comprises the levator ani and the ischiococcygeus | ||||
| perineum | diamond-shaped region between the pubic symphysis, coccyx, and ischial tuberosities | ||||
| pubococcygeus | muscle that makes up the levator ani along with the iliococcygeus | ||||
| quadratus lumborum | posterior part of the abdominal wall that helps with posture and stabilization of the body | ||||
| rectus abdominis | long, linear muscle that extends along the middle of the trunk | ||||
| rectus sheaths | tissue that makes up the linea alba | ||||
| sphincter urethrovaginalis | deep perineal muscle in women | ||||
| tendinous intersections | three transverse bands of collagen fibers that divide the rectus abdominis into segments | ||||
| transversus abdominis | deep layer of the abdomen that has fascicles arranged transversely around the abdomen | ||||
| urogenital triangle | anterior triangle of the perineum that includes the external genitals | ||||
| abductor digiti minimi | muscle that abducts the little finger | ||||
| adductor pollicis | muscle that adducts the thumb | ||||
| abductor pollicis brevis | muscle that abducts the thumb | ||||
| abductor pollicis longus | muscle that inserts into the first metacarpal | ||||
| anconeus | small muscle on the lateral posterior elbow that extends the forearm | ||||
| anterior compartment of the arm | (anterior flexor compartment of the arm) the biceps brachii, brachialis, brachioradialis, and their associated blood vessels and nerves | ||||
| anterior compartment of the forearm | (anterior flexor compartment of the forearm) deep and superficial muscles that originate on the humerus and insert into the hand | ||||
| biceps brachii | two-headed muscle that crosses the shoulder and elbow joints to flex the forearm while assisting in supinating it and flexing the arm at the shoulder | ||||
| brachialis | muscle deep to the biceps brachii that provides power in flexing the forearm. | ||||
| brachioradialis | muscle that can flex the forearm quickly or help lift a load slowly | ||||
| coracobrachialis | muscle that flexes and adducts the arm | ||||
| deep anterior compartment | flexor pollicis longus, flexor digitorum profundus, and their associated blood vessels and nerves | ||||
| deep posterior compartment of the forearm | (deep posterior extensor compartment of the forearm) the abductor pollicis longus, extensor pollicis brevis, extensor pollicis longus, extensor indicis, and their associated blood vessels and nerves | ||||
| deltoid | shoulder muscle that abducts the arm as well as flexes and medially rotates it, and extends and laterally rotates it | ||||
| dorsal interossei | muscles that abduct and flex the three middle fingers at the metacarpophalangeal joints and extend them at the interphalangeal joints | ||||
| extensor carpi radialis brevis | muscle that extends and abducts the hand at the wrist | ||||
| extensor carpi ulnaris | muscle that extends and adducts the hand | ||||
| extensor digiti minimi | muscle that extends the little finger | ||||
| extensor digitorum | muscle that extends the hand at the wrist and the phalanges | ||||
| extensor indicis | muscle that inserts onto the tendon of the extensor digitorum of the index finger | ||||
| extensor pollicis brevis | muscle that inserts onto the base of the proximal phalanx of the thumb | ||||
| extensor pollicis longus | muscle that inserts onto the base of the distal phalanx of the thumb | ||||
| extensor radialis longus | muscle that extends and abducts the hand at the wrist | ||||
| extensor retinaculum | band of connective tissue that extends over the dorsal surface of the hand | ||||
| extrinsic muscles of the hand | muscles that move the wrists, hands, and fingers and originate on the arm | ||||
| flexor carpi radialis | muscle that flexes and abducts the hand at the wrist | ||||
| flexor carpi ulnaris | muscle that flexes and adducts the hand at the wrist | ||||
| flexor digiti minimi brevis | muscle that flexes the little finger | ||||
| flexor digitorum profundus | muscle that flexes the phalanges of the fingers and the hand at the wrist | ||||
| flexor digitorum superficialis | muscle that flexes the hand and the digits | ||||
| flexor pollicis brevis | muscle that flexes the thumb | ||||
| flexor pollicis longus | muscle that flexes the distal phalanx of the thumb | ||||
| flexor retinaculum | band of connective tissue that extends over the palmar surface of the hand | ||||
| hypothenar | group of muscles on the medial aspect of the palm | ||||
| hypothenar eminence | rounded contour of muscle at the base of the little finger | ||||
| infraspinatus | muscle that laterally rotates the arm | ||||
| intermediate | group of midpalmar muscles | ||||
| intrinsic muscles of the hand | muscles that move the wrists, hands, and fingers and originate in the palm | ||||
| latissimus dorsi | broad, triangular axial muscle located on the inferior part of the back | ||||
| lumbrical | muscle that flexes each finger at the metacarpophalangeal joints and extend each finger at the interphalangeal joints | ||||
| opponens digiti minimi | muscle that brings the little finger across the palm to meet the thumb | ||||
| opponens pollicis | muscle that moves the thumb across the palm to meet another finger | ||||
| palmar interossei | muscles that abduct and flex each finger at the metacarpophalangeal joints and extend each finger at the interphalangeal joints | ||||
| palmaris longus | muscle that provides weak flexion of the hand at the wrist | ||||
| pectoral girdle | shoulder girdle, made up of the clavicle and scapula | ||||
| pectoralis major | thick, fan-shaped axial muscle that covers much of the superior thorax | ||||
| pectoralis minor | muscle that moves the scapula and assists in inhalation | ||||
| pronator quadratus | pronator that originates on the ulna and inserts on the radius | ||||
| pronator teres | pronator that originates on the humerus and inserts on the radius | ||||
| retinacula | fibrous bands that sheath the tendons at the wrist | ||||
| rhomboid major | muscle that attaches the vertebral border of the scapula to the spinous process of the thoracic vertebrae | ||||
| rhomboid minor | muscle that attaches the vertebral border of the scapula to the spinous process of the thoracic vertebrae | ||||
| rotator cuff | (also, musculotendinous cuff) the circle of tendons around the shoulder joint | ||||
| serratus anterior | large and flat muscle that originates on the ribs and inserts onto the scapula | ||||
| subclavius | muscle that stabilizes the clavicle during movement | ||||
| subscapularis | muscle that originates on the anterior scapula and medially rotates the arm | ||||
| superficial anterior compartment of the forearm | flexor carpi radialis, palmaris longus, flexor carpi ulnaris, flexor digitorum superficialis, and their associated blood vessels and nerves | ||||
| superficial posterior compartment of the forearm | extensor radialis longus, extensor carpi radialis brevis, extensor digitorum, extensor digiti minimi, extensor carpi ulnaris, and their associated blood vessels and nerves | ||||
| supinator | muscle that moves the palm and forearm anteriorly | ||||
| supraspinatus | muscle that abducts the arm | ||||
| teres major | muscle that extends the arm and assists in adduction and medial rotation of it | ||||
| teres minor | muscle that laterally rotates and extends the arm | ||||
| thenar | group of muscles on the lateral aspect of the palm | ||||
| thenar eminence | rounded contour of muscle at the base of the thumb | ||||
| trapezius | muscle that stabilizes the upper part of the back | ||||
| triceps brachii | three-headed muscle that extends the forearm | ||||
| adductor brevis | muscle that adducts and medially rotates the thigh | ||||
| adductor longus | muscle that adducts, medially rotates, and flexes the thigh | ||||
| adductor magnus | muscle with an anterior fascicle that adducts, medially rotates and flexes the thigh, and a posterior fascicle that assists in thigh extension | ||||
| anterior compartment of the leg | region that includes muscles that dorsiflex the foot | ||||
| anterior compartment of the thigh | region that includes muscles that flex the thigh and extend the leg | ||||
| biceps femoris | hamstring muscle | ||||
| calcaneal tendon | (also, Achilles tendon) strong tendon that inserts into the calcaneal bone of the ankle | ||||
| dorsal group | region that includes the extensor digitorum brevis | ||||
| extensor digitorum brevis | muscle that extends the toes | ||||
| extensor digitorum longus | muscle that is lateral to the tibialis anterior | ||||
| extensor hallucis longus | muscle that is partly deep to the tibialis anterior and extensor digitorum longus | ||||
| femoral triangle | region formed at the junction between the hip and the leg and includes the pectineus, femoral nerve, femoral artery, femoral vein, and deep inguinal lymph nodes | ||||
| fibularis brevis | (also, peroneus brevis) muscle that plantar flexes the foot at the ankle and everts it at the intertarsal joints | ||||
| fibularis longus | (also, peroneus longus) muscle that plantar flexes the foot at the ankle and everts it at the intertarsal joints | ||||
| fibularis tertius | small muscle that is associated with the extensor digitorum longus | ||||
| flexor digitorum longus | muscle that flexes the four small toes | ||||
| flexor hallucis longus | muscle that flexes the big toe | ||||
| gastrocnemius | most superficial muscle of the calf | ||||
| gluteal group | muscle group that extends, flexes, rotates, adducts, and abducts the femur | ||||
| gluteus maximus | largest of the gluteus muscles that extends the femur | ||||
| gluteus medius | muscle deep to the gluteus maximus that abducts the femur at the hip | ||||
| gluteus minimus | smallest of the gluteal muscles and deep to the gluteus medius | ||||
| gracilis | muscle that adducts the thigh and flexes the leg at the knee | ||||
| hamstring group | three long muscles on the back of the leg | ||||
| iliacus | muscle that, along with the psoas major, makes up the iliopsoas | ||||
| iliopsoas group | muscle group consisting of iliacus and psoas major muscles, that flexes the thigh at the hip, rotates it laterally, and flexes the trunk of the body onto the hip | ||||
| iliotibial tract | muscle that inserts onto the tibia; made up of the gluteus maximus and connective tissues of the tensor fasciae latae | ||||
| inferior extensor retinaculum | cruciate ligament of the ankle | ||||
| inferior gemellus | muscle deep to the gluteus maximus on the lateral surface of the thigh that laterally rotates the femur at the hip | ||||
| lateral compartment of the leg | region that includes the fibularis (peroneus) longus and the fibularis (peroneus) brevis and their associated blood vessels and nerves | ||||
| medial compartment of the thigh | a region that includes the adductor longus, adductor brevis, adductor magnus, pectineus, gracilis, and their associated blood vessels and nerves | ||||
| obturator externus | muscle deep to the gluteus maximus on the lateral surface of the thigh that laterally rotates the femur at the hip | ||||
| obturator internus | muscle deep to the gluteus maximus on the lateral surface of the thigh that laterally rotates the femur at the hip | ||||
| patellar ligament | extension of the quadriceps tendon below the patella | ||||
| pectineus | muscle that abducts and flexes the femur at the hip | ||||
| pelvic girdle | hips, a foundation for the lower limb | ||||
| piriformis | muscle deep to the gluteus maximus on the lateral surface of the thigh that laterally rotates the femur at the hip | ||||
| plantar aponeurosis | muscle that supports the longitudinal arch of the foot | ||||
| plantar group | four-layered group of intrinsic foot muscles | ||||
| plantaris | muscle that runs obliquely between the gastrocnemius and the soleus | ||||
| popliteal fossa | diamond-shaped space at the back of the knee | ||||
| popliteus | muscle that flexes the leg at the knee and creates the floor of the popliteal fossa | ||||
| posterior compartment of the leg | region that includes the superficial gastrocnemius, soleus, and plantaris, and the deep popliteus, flexor digitorum longus, flexor hallucis longus, and tibialis posterior | ||||
| posterior compartment of the thigh | region that includes muscles that flex the leg and extend the thigh | ||||
| psoas major | muscle that, along with the iliacus, makes up the iliopsoas | ||||
| quadratus femoris | muscle deep to the gluteus maximus on the lateral surface of the thigh that laterally rotates the femur at the hip | ||||
| quadriceps femoris group | four muscles, that extend and stabilize the knee | ||||
| quadriceps tendon | (also, patellar tendon) tendon common to all four quadriceps muscles, inserts into the patella | ||||
| rectus femoris | quadricep muscle on the anterior aspect of the thigh | ||||
| sartorius | band-like muscle that flexes, abducts, and laterally rotates the leg at the hip | ||||
| semimembranosus | hamstring muscle | ||||
| semitendinosus | hamstring muscle | ||||
| soleus | wide, flat muscle deep to the gastrocnemius | ||||
| superior extensor retinaculum | transverse ligament of the ankle | ||||
| superior gemellus | muscle deep to the gluteus maximus on the lateral surface of the thigh that laterally rotates the femur at the hip | ||||
| tensor fascia lata | muscle that flexes and abducts the thigh | ||||
| tibialis anterior | muscle located on the lateral surface of the tibia | ||||
| tibialis posterior | muscle that plantar flexes and inverts the foot | ||||
| vastus intermedius | quadricep muscle that is between the vastus lateralis and vastus medialis and is deep to the rectus femoris | ||||
| vastus lateralis | quadricep muscle on the lateral aspect of the thigh | ||||
| vastus medialis | quadricep muscle on the medial aspect of the thigh | ||||
| autonomic nervous system (ANS) | functional division of the nervous system that is responsible for homeostatic reflexes that coordinate control of cardiac and smooth muscle, as well as glandular tissue | ||||
| axon | single process of the neuron that carries an electrical signal (action potential) away from the cell body toward a target cell | ||||
| brain | the large organ of the central nervous system composed of white and gray matter, contained within the cranium and continuous with the spinal cord | ||||
| central nervous system (CNS) | anatomical division of the nervous system located within the cranial and vertebral cavities, namely the brain and spinal cord | ||||
| dendrite | one of many branchlike processes that extends from the neuron cell body and functions as a contact for incoming signals (synapses) from other neurons or sensory cells | ||||
| enteric nervous system (ENS) | neural tissue associated with the digestive system that is responsible for nervous control through autonomic connections | ||||
| ganglion | localized collection of neuron cell bodies in the peripheral nervous system | ||||
| glial cell | one of the various types of neural tissue cells responsible for maintenance of the tissue, and largely responsible for supporting neurons | ||||
| gray matter | regions of the nervous system containing cell bodies of neurons with few or no myelinated axons; actually may be more pink or tan in color, but called gray in contrast to white matter | ||||
| integration | nervous system function that combines sensory perceptions and higher cognitive functions (memories, learning, emotion, etc.) to produce a response | ||||
| myelin | lipid-rich insulating substance surrounding the axons of many neurons, allowing for faster transmission of electrical signals | ||||
| nerve | cord-like bundle of axons located in the peripheral nervous system that transmits sensory input and response output to and from the central nervous system | ||||
| neuron | neural tissue cell that is primarily responsible for generating and propagating electrical signals into, within, and out of the nervous system | ||||
| nucleus | in the nervous system, a localized collection of neuron cell bodies that are functionally related; a “center” of neural function | ||||
| peripheral nervous system (PNS) | anatomical division of the nervous system that is largely outside the cranial and vertebral cavities, namely all parts except the brain and spinal cord | ||||
| process | in cells, an extension of a cell body; in the case of neurons, this includes the axon and dendrites | ||||
| response | nervous system function that causes a target tissue (muscle or gland) to produce an event as a consequence to stimuli | ||||
| sensation | nervous system function that receives information from the environment and translates it into the electrical signals of nervous tissue | ||||
| soma | in neurons, that portion of the cell that contains the nucleus; the cell body, as opposed to the cell processes (axons and dendrites) | ||||
| somatic nervous system (SNS) | functional division of the nervous system that is concerned with conscious perception, voluntary movement, and skeletal muscle reflexes | ||||
| spinal cord | organ of the central nervous system found within the vertebral cavity and connected with the periphery through spinal nerves; mediates reflex behaviors | ||||
| stimulus | an event in the external or internal environment that registers as activity in a sensory neuron | ||||
| tract | bundle of axons in the central nervous system having the same function and point of origin | ||||
| white matter | regions of the nervous system containing mostly myelinated axons, making the tissue appear white because of the high lipid content of myelin | ||||
| astrocyte | glial cell type of the CNS that provides support for neurons and maintains the blood-brain barrier | ||||
| axon hillock | tapering of the neuron cell body that gives rise to the axon | ||||
| axon segment | single stretch of the axon insulated by myelin and bounded by nodes of Ranvier at either end (except for the first, which is after the initial segment, and the last, which is followed by the axon terminal) | ||||
| axon terminal | end of the axon, where there are usually several branches extending toward the target cell | ||||
| axoplasm | cytoplasm of an axon, which is different in composition than the cytoplasm of the neuronal cell body | ||||
| bipolar | shape of a neuron with two processes extending from the neuron cell body—the axon and one dendrite | ||||
| blood-brain barrier (BBB) | physiological barrier between the circulatory system and the central nervous system that establishes a privileged blood supply, restricting the flow of substances into the CNS | ||||
| cerebrospinal fluid (CSF) | circulatory medium within the CNS that is produced by ependymal cells in the choroid plexus filtering the blood | ||||
| choroid plexus | specialized structure containing ependymal cells that line blood capillaries and filter blood to produce CSF in the four ventricles of the brain | ||||
| ependymal cell | glial cell type in the CNS responsible for producing cerebrospinal fluid | ||||
| initial segment | first part of the axon as it emerges from the axon hillock, where the electrical signals known as action potentials are generated | ||||
| interneuron | functional classification of a neuron that integrates information between sensory and motor neurons | ||||
| microglia | glial cell type in the CNS that serves as the resident component of the immune system | ||||
| motor neuron | functional classification of a neuron that carries commands from the brain and spinal cord to muscles and glands | ||||
| multipolar | shape of a neuron that has multiple processes—the axon and two or more dendrites | ||||
| myelin sheath | lipid-rich layer of insulation that surrounds an axon, formed by oligodendrocytes in the CNS and Schwann cells in the PNS; facilitates the transmission of electrical signals | ||||
| neuronal polarity | asymmetrical distribution of cellular components (dendrites and axon) within a neuron | ||||
| node of Ranvier | gap between two myelinated regions of an axon, allowing for strengthening of the electrical signal as it propagates down the axon | ||||
| oligodendrocyte | glial cell type in the CNS that provides the myelin insulation for axons in tracts | ||||
| satellite cell | glial cell type in the PNS that provides support for neurons in the ganglia | ||||
| Schwann cell | glial cell type in the PNS that provides the myelin insulation for axons in nerves | ||||
| sensory neuron | functional classification of a neuron that carries sensory information from the body's periphery into the nervous system | ||||
| synapse | narrow junction across which a chemical signal passes from neuron to the next, initiating a new electrical signal in the target cell | ||||
| synaptic end bulb | swelling at the end of an axon where neurotransmitter molecules are released onto a target cell across a synapse | ||||
| unipolar | shape of a neuron which has only one process that includes both the axon and dendrite | ||||
| ventricle | central cavity within the brain where CSF is produced and circulates | ||||
| action potential | change in the electrical properties of a cell membrane in response to a stimulus that results in transmission of an electrical signal; unique to neurons and muscle fibers | ||||
| All-or-None Law | the principle that the strength by which a neuron responds to a stimulus is not dependent on the strength of the stimulus; | ||||
| cerebral cortex | outermost layer of gray matter in the brain, where conscious perception takes place | ||||
| chemical synapse | connection between two neurons, or between a neuron and its target, where a neurotransmitter diffuses across a very short distance | ||||
| continuous conduction | slower propagation of the action potential along an unmyelinated axon | ||||
| electrical synapse | connection between two neurons, or any two electrically active cells, where an action potential can flow across gap junctions into the adjacent cell | ||||
| lower motor neuron | second neuron in the motor command pathway that is directly connected to the skeletal muscle | ||||
| neurotransmitter | chemical signal that is released from the synaptic end bulb of a neuron to cause a change in the target cell | ||||
| postsynaptic cell | cell receiving a synapse from another cell | ||||
| precentral gyrus of the frontal cortex | region of the cerebral cortex responsible for generating motor commands, where the upper motor neuron cell body is located | ||||
| presynaptic cell | cell forming a synapse with another cell | ||||
| propagation | movement of an action potential along the length of an axon | ||||
| saltatory conduction | faster propagation of the action potential in a myelinated axon, from one node of Ranvier to the following node | ||||
| synaptic cleft | small gap between cells in a chemical synapse where neurotransmitter diffuses from the presynaptic element to the postsynaptic element | ||||
| thalamus | region of the central nervous system that acts as a relay for sensory pathways | ||||
| thermoreceptor | type of sensory receptor capable of transducing temperature stimuli into neural action potentials | ||||
| threshold | membrane voltage at which an action potential is initiated | ||||
| upper motor neuron | first neuron in the motor command pathway with its cell body in the cerebral cortex that synapses on the lower motor neuron in the spinal cord | ||||
| brain stem | region of the adult brain that includes the midbrain, pons, and medulla oblongata and develops from the mesencephalon, metencephalon, and myelencephalon of the embryonic brain | ||||
| cephalic flexure | curve in midbrain of the embryo that positions the forebrain ventrally | ||||
| diencephalon | region of the adult brain that retains its name from embryonic development and includes the thalamus and hypothalamus | ||||
| forebrain | anterior region of the adult brain that develops from the prosencephalon and includes the cerebrum and diencephalon | ||||
| hindbrain | posterior region of the adult brain that develops from the rhombencephalon and includes the pons, medulla oblongata, and cerebellum | ||||
| mesencephalon | primary vesicle of the embryonic brain that does not significantly change through the rest of embryonic development and becomes the midbrain | ||||
| metencephalon | secondary vesicle of the embryonic brain that develops into the pons and the cerebellum | ||||
| midbrain | middle region of the adult brain that develops from the mesencephalon | ||||
| myelencephalon | secondary vesicle of the embryonic brain that develops into the medulla | ||||
| neural crest | tissue that detaches from the edges of the neural groove and migrates through the embryo to develop into peripheral structures of both nervous and non-nervous tissues | ||||
| neural fold | elevated edge of the neural groove | ||||
| neural groove | region of the neural plate that folds into the dorsal surface of the embryo and closes off to become the neural tube | ||||
| neural plate | thickened layer of neuroepithelium that runs longitudinally along the dorsal surface of an embryo and gives rise to nervous system tissue | ||||
| neural tube | precursor to structures of the central nervous system, formed by the invagination and separation of neuroepithelium | ||||
| neuraxis | central axis to the nervous system, from the posterior to anterior ends of the neural tube; the inferior tip of the spinal cord to the anterior surface of the cerebrum | ||||
| primary vesicle | initial enlargements of the anterior neural tube during embryonic development that develop into the forebrain, midbrain, and hindbrain | ||||
| prosencephalon | primary vesicle of the embryonic brain that develops into the forebrain, which includes the cerebrum and diencephalon | ||||
| rhombencephalon | primary vesicle of the embryonic brain that develops into the hindbrain, which includes the pons, cerebellum, and medulla | ||||
| secondary vesicle | five vesicles that develop from primary vesicles, continuing the process of differentiation of the embryonic brain | ||||
| telencephalon | secondary vesicle of the embryonic brain that develops into the cerebrum | ||||
| anterior spinal artery | blood vessel from the merged branches of the vertebral arteries that runs along the anterior surface of the spinal cord | ||||
| arachnoid granulation | outpocket of the arachnoid membrane into the dural sinuses that allows for reabsorption of CSF into the blood | ||||
| arachnoid mater | middle layer of the meninges named for the spider-web–like trabeculae that extend between it and the pia mater | ||||
| arachnoid trabeculae | filaments between the arachnoid and pia mater within the subarachnoid space | ||||
| basilar artery | blood vessel from the merged vertebral arteries that runs along the dorsal surface of the brain stem | ||||
| carotid canal | opening in the temporal bone through which the internal carotid artery enters the cranium | ||||
| central canal | hollow space within the spinal cord that is the remnant of the center of the neural tube | ||||
| cerebral aqueduct | connection of the ventricular system between the third and fourth ventricles located in the midbrain | ||||
| choroid plexus | specialized structures containing ependymal cells lining blood capillaries that filter blood to produce CSF in the four ventricles of the brain | ||||
| circle of Willis | unique anatomical arrangement of blood vessels around the base of the brain that maintains perfusion of blood into the brain even if one component of the structure is blocked or narrowed | ||||
| common carotid artery | blood vessel that branches off the aorta (or the brachiocephalic artery on the right) and supplies blood to the head and neck | ||||
| dura mater | tough, fibrous, outer layer of the meninges that is attached to the inner surface of the cranium and vertebral column and surrounds the entire CNS | ||||
| dural sinus | any of the venous structures surrounding the brain, enclosed within the dura mater, which drain blood from the CNS to the common venous return of the jugular veins | ||||
| foramen magnum | large opening in the occipital bone of the skull through which the spinal cord emerges and the vertebral arteries enter the cranium | ||||
| fourth ventricle | the portion of the ventricular system that is in the region of the brain stem and opens into the subarachnoid space through the median and lateral apertures | ||||
| internal carotid artery | branch from the common carotid artery that enters the cranium and supplies blood to the brain | ||||
| interventricular foramina | openings between the lateral ventricles and third ventricle allowing for the passage of CSF | ||||
| jugular veins | blood vessels that return “used” blood from the head and neck | ||||
| lateral apertures | pair of openings from the fourth ventricle to the subarachnoid space on either side and between the medulla and cerebellum | ||||
| lateral ventricles | portions of the ventricular system that are in the region of the cerebrum | ||||
| lumbar puncture | procedure used to withdraw CSF from the lower lumbar region of the vertebral column that avoids the risk of damaging CNS tissue because the spinal cord ends at the upper lumbar vertebrae | ||||
| median aperture | singular opening from the fourth ventricle into the subarachnoid space at the midline between the medulla and cerebellum | ||||
| meninges | protective outer coverings of the CNS composed of connective tissue | ||||
| occipital sinuses | dural sinuses along the edge of the occipital lobes of the cerebrum | ||||
| orthostatic reflex | sympathetic function that maintains blood pressure when standing to offset the increased effect of gravity | ||||
| pia mater | thin, innermost membrane of the meninges that directly covers the surface of the CNS | ||||
| sigmoid sinuses | dural sinuses that drain directly into the jugular veins | ||||
| straight sinus | dural sinus that drains blood from the deep center of the brain to collect with the other sinuses | ||||
| subarachnoid space | space between the arachnoid mater and pia mater that contains CSF and the fibrous connections of the arachnoid trabeculae | ||||
| superior sagittal sinus | dural sinus that runs along the top of the longitudinal fissure and drains blood from the majority of the outer cerebrum | ||||
| third ventricle | portion of the ventricular system that is in the region of the diencephalon | ||||
| transverse sinuses | dural sinuses that drain along either side of the occipital–cerebellar space | ||||
| ventricles | remnants of the hollow center of the neural tube that are spaces for cerebrospinal fluid to circulate through the brain | ||||
| amygdala | nucleus deep in the temporal lobe of the cerebrum that is related to memory and emotional behavior | ||||
| ascending tract | central nervous system fibers carrying sensory information from the spinal cord or periphery to the brain | ||||
| ataxia | movement disorder related to damage of the cerebellum characterized by loss of coordination in voluntary movements | ||||
| basal forebrain | nuclei of the cerebrum related to modulation of sensory stimuli and attention through broad projections to the cerebral cortex, loss of which is related to Alzheimer’s disease | ||||
| basal nuclei | nuclei of the cerebrum (with a few components in the upper brain stem and diencephalon) that are responsible for assessing cortical movement commands and comparing them with the general state of the individual through broad modulatory activity of dopamine neurons; largely related to motor functions, as evidenced through the symptoms of Parkinson’s and Huntington’s diseases | ||||
| Broca’s area | region of the frontal lobe associated with the motor commands necessary for speech production and located only in the cerebral hemisphere responsible for language production, which is the left side in approximately 95 percent of the population | ||||
| Brodmann’s areas | mapping of regions of the cerebral cortex based on microscopic anatomy that relates specific areas to functional differences, as described by Brodmann in the early 1900s | ||||
| caudate | nucleus deep in the cerebrum that is part of the basal nuclei; along with the putamen, it is part of the striatum | ||||
| central sulcus | surface landmark of the cerebral cortex that marks the boundary between the frontal and parietal lobes | ||||
| cerebral cortex | outer gray matter covering the forebrain, marked by wrinkles and folds known as gyri and sulci | ||||
| cerebrum | region of the adult brain that develops from the telencephalon and is responsible for higher neurological functions such as memory, emotion, and consciousness | ||||
| cerebellum | region of the adult brain connected primarily to the pons that developed from the metencephalon (along with the pons) and is largely responsible for comparing information from the cerebrum with sensory feedback from the periphery through the spinal cord | ||||
| cerebral hemisphere | one half of the bilaterally symmetrical cerebrum | ||||
| corpus callosum | large white matter structure that connects the right and left cerebral hemispheres | ||||
| descending tract | central nervous system fibers carrying motor commands from the brain to the spinal cord or periphery | ||||
| direct pathway | connections within the basal nuclei from the striatum to the globus pallidus internal segment and substantia nigra pars reticulata that disinhibit the thalamus to increase cortical control of movement | ||||
| disinhibition | disynaptic connection in which the first synapse inhibits the second cell, which then stops inhibiting the final target | ||||
| epithalamus | region of the diecephalon containing the pineal gland | ||||
| frontal eye field | region of the frontal lobe associated with motor commands to orient the eyes toward an object of visual attention | ||||
| frontal lobe | region of the cerebral cortex directly beneath the frontal bone of the cranium | ||||
| gait | rhythmic pattern of alternating movements of the lower limbs during locomotion | ||||
| globus pallidus | nuclei deep in the cerebrum that are part of the basal nuclei and can be divided into the internal and external segments | ||||
| gyrus | ridge formed by convolutions on the surface of the cerebrum or cerebellum | ||||
| hippocampus | gray matter deep in the temporal lobe that is very important for long-term memory formation | ||||
| hypothalamus | major region of the diencephalon that is responsible for coordinating autonomic and endocrine control of homeostasis | ||||
| indirect pathway | connections within the basal nuclei from the striatum through the globus pallidus external segment and subthalamic nucleus to the globus pallidus internal segment/substantia nigra pars compacta that result in inhibition of the thalamus to decrease cortical control of movement | ||||
| inferior cerebellar peduncle (ICP) | input to the cerebellum, largely from the inferior olive, that represents sensory feedback from the periphery | ||||
| inferior colliculus | half of the midbrain tectum that is part of the brain stem auditory pathway | ||||
| inferior olive | nucleus in the medulla that is involved in processing information related to motor control | ||||
| kinesthesia | general sensory perception of movement of the body | ||||
| lateral sulcus | surface landmark of the cerebral cortex that marks the boundary between the temporal lobe and the frontal and parietal lobes | ||||
| limbic cortex | collection of structures of the cerebral cortex that are involved in emotion, memory, and behavior and are part of the larger limbic system | ||||
| limbic system | structures at the edge (limit) of the boundary between the forebrain and hindbrain that are most associated with emotional behavior and memory formation | ||||
| longitudinal fissure | large separation along the midline between the two cerebral hemispheres | ||||
| middle cerebellar peduncle (MCP) | large, white-matter bridge from the pons that constitutes the major input to the cerebellar cortex | ||||
| occipital lobe | region of the cerebral cortex directly beneath the occipital bone of the cranium | ||||
| olfaction | special sense responsible for smell, which has a unique, direct connection to the cerebrum | ||||
| parietal lobe | region of the cerebral cortex directly beneath the parietal bone of the cranium | ||||
| parieto-occipital sulcus | groove in the cerebral cortex representing the border between the parietal and occipital cortices | ||||
| postcentral gyrus | ridge just posterior to the central sulcus, in the parietal lobe, where somatosensory processing initially takes place in the cerebrum | ||||
| precentral gyrus | primary motor cortex located in the frontal lobe of the cerebral cortex | ||||
| prefrontal lobe | specific region of the frontal lobe anterior to the more specific motor function areas, which can be related to the early planning of movements and intentions to the point of being personality-type functions | ||||
| premotor area | region of the frontal lobe responsible for planning movements that will be executed through the primary motor cortex | ||||
| proprioception | general sensory perceptions providing information about location and movement of body parts; the “sense of the self” | ||||
| putamen | nucleus deep in the cerebrum that is part of the basal nuclei; along with the caudate, it is part of the striatum | ||||
| reticular formation | diffuse region of gray matter throughout the brain stem that regulates sleep, wakefulness, and states of consciousness | ||||
| somatosensation | general senses related to the body, usually thought of as the senses of touch, which would include pain, temperature, and proprioception | ||||
| striatum | the caudate and putamen collectively, as part of the basal nuclei, which receive input from the cerebral cortex | ||||
| subcortical nucleus | all the nuclei beneath the cerebral cortex, including the basal nuclei and the basal forebrain | ||||
| substantia nigra pars compacta | nuclei within the basal nuclei that release dopamine to modulate the function of the striatum; part of the motor pathway | ||||
| substantia nigra pars reticulata | nuclei within the basal nuclei that serve as an output center of the nuclei; part of the motor pathway | ||||
| subthalamus | nucleus within the basal nuclei that is part of the indirect pathway | ||||
| sulcus | groove formed by convolutions in the surface of the cerebral cortex | ||||
| superior cerebellar peduncle (SCP) | white-matter tract representing output of the cerebellum to the red nucleus of the midbrain | ||||
| superior colliculus | half of the midbrain tectum that is responsible for aligning visual, auditory, and somatosensory spatial perceptions | ||||
| tectum | region of the midbrain, thought of as the roof of the cerebral aqueduct, which is subdivided into the inferior and superior colliculi | ||||
| tegmentum | region of the midbrain, thought of as the floor of the cerebral aqueduct, which continues into the pons and medulla as the floor of the fourth ventricle | ||||
| temporal lobe | region of the cerebral cortex directly beneath the temporal bone of the cranium | ||||
| vermis | prominent ridge along the midline of the cerebellum that is referred to as the spinocerebellum | ||||
| thalamus | major region of the diencephalon that is responsible for relaying information between the cerebrum and the hindbrain, spinal cord, and periphery | ||||
| alar plate | developmental region of the spinal cord that gives rise to the posterior horn of the gray matter | ||||
| anterior column | white matter between the anterior horns of the spinal cord composed of many different groups of axons of both ascending and descending tracts | ||||
| anterior horn | gray matter of the spinal cord containing multipolar motor neurons, sometimes referred to as the ventral horn | ||||
| anterior median fissure | deep midline feature of the anterior spinal cord, marking the separation between the right and left sides of the cord | ||||
| ascending tract | central nervous system fibers carrying sensory information from the spinal cord or periphery to the brain | ||||
| basal plate | developmental region of the spinal cord that gives rise to the lateral and anterior horns of gray matter | ||||
| cauda equina | bundle of spinal nerve roots that descend from the lower spinal cord below the first lumbar vertebra and lie within the vertebral cavity; has the appearance of a horse's tail | ||||
| descending tract | central nervous system fibers carrying motor commands from the brain to the spinal cord or periphery | ||||
| dorsal (posterior) nerve root | axons entering the posterior horn of the spinal cord | ||||
| lateral column | white matter of the spinal cord between the posterior horn on one side and the axons from the anterior horn on the same side; composed of many different groups of axons, of both ascending and descending tracts, carrying motor commands to and from the brain | ||||
| lateral horn | region of the spinal cord gray matter in the thoracic, upper lumbar, and sacral regions that is the central component of the sympathetic division of the autonomic nervous system | ||||
| posterior columns | white matter of the spinal cord that lies between the posterior horns of the gray matter, sometimes referred to as the dorsal column; composed of axons of ascending tracts that carry sensory information up to the brain | ||||
| posterior horn | gray matter region of the spinal cord in which sensory input arrives, sometimes referred to as the dorsal horn | ||||
| posterior median sulcus | midline feature of the posterior spinal cord, marking the separation between right and left sides of the cord | ||||
| posterolateral sulcus | feature of the posterior spinal cord marking the entry of posterior nerve roots and the separation between the posterior and lateral columns of the white matter | ||||
| ventral (anterior) nerve root | axons emerging from the anterior or lateral horns of the spinal cord | ||||
| abducens nerve | sixth cranial nerve; responsible for contraction of one of the extraocular muscles | ||||
| axillary nerve | systemic nerve of the arm that arises from the brachial plexus | ||||
| brachial plexus | nerve plexus associated with the lower cervical spinal nerves and first thoracic spinal nerve | ||||
| cervical plexus | nerve plexus associated with the upper cervical spinal nerves | ||||
| cranial nerve | one of twelve nerves connected to the brain that are responsible for sensory or motor functions of the head and neck | ||||
| cranial nerve ganglion | sensory ganglion of cranial nerves | ||||
| dorsal (posterior) root ganglion | sensory ganglion attached to the posterior nerve root of a spinal nerve | ||||
| endoneurium | innermost layer of connective tissue that surrounds individual axons within a nerve | ||||
| enteric nervous system | peripheral structures, namely ganglia and nerves, that are incorporated into the digestive system organs | ||||
| enteric plexus | neuronal plexus in the wall of the intestines, which is part of the enteric nervous system | ||||
| epineurium | outermost layer of connective tissue that surrounds an entire nerve | ||||
| esophageal plexus | neuronal plexus in the wall of the esophagus that is part of the enteric nervous system | ||||
| extraocular muscles | six skeletal muscles that control eye movement within the orbit | ||||
| facial nerve | seventh cranial nerve; responsible for contraction of the facial muscles and for part of the sense of taste, as well as causing saliva production | ||||
| fascicle | small bundles of nerve or muscle fibers enclosed by connective tissue | ||||
| femoral nerve | systemic nerve of the anterior leg that arises from the lumbar plexus | ||||
| fibular nerve | systemic nerve of the posterior leg that begins as part of the sciatic nerve | ||||
| gastric plexuses | neuronal networks in the wall of the stomach that are part of the enteric nervous system | ||||
| glossopharyngeal nerve | ninth cranial nerve; responsible for contraction of muscles in the tongue and throat and for part of the sense of taste, as well as causing saliva production | ||||
| hypoglossal nerve | twelfth cranial nerve; responsible for contraction of muscles of the tongue | ||||
| intercostal nerve | systemic nerve in the thoracic cavity that is found between two ribs | ||||
| lumbar plexus | nerve plexus associated with the lumbar spinal nerves | ||||
| median nerve | systemic nerve of the arm, located between the ulnar and radial nerves | ||||
| nerve plexus | network of nerves without neuronal cell bodies included | ||||
| oculomotor nerve | third cranial nerve; responsible for contraction of four of the extraocular muscles, the muscle in the upper eyelid, and pupillary constriction | ||||
| olfactory nerve | first cranial nerve; responsible for the sense of smell | ||||
| optic nerve | second cranial nerve; responsible for visual sensation | ||||
| paravertebral ganglia | autonomic ganglia superior to the sympathetic chain ganglia | ||||
| perineurium | layer of connective tissue surrounding fascicles within a nerve | ||||
| phrenic nerve | systemic nerve from the cervical plexus that enervates the diaphragm | ||||
| plexus | network of nerves or nervous tissue | ||||
| prevertebral ganglia | autonomic ganglia that are anterior to the vertebral column and functionally related to the sympathetic chain ganglia | ||||
| radial nerve | systemic nerve of the arm, the distal component of which is located near the radial bone | ||||
| sacral plexus | nerve plexus associated with the lower lumbar and sacral spinal nerves | ||||
| saphenous nerve | systemic nerve of the lower anterior leg that is a branch from the femoral nerve | ||||
| sciatic nerve | systemic nerve from the sacral plexus that is a combination of the tibial and fibular nerves and extends across the hip joint and gluteal region into the upper posterior leg | ||||
| sciatica | painful condition resulting from inflammation or compression of the sciatic nerve or any of the spinal nerves that contribute to it | ||||
| spinal accessory nerve | eleventh cranial nerve; responsible for contraction of neck muscles | ||||
| spinal nerve | one of 31 nerves connected to the spinal cord | ||||
| sympathetic chain ganglia | autonomic ganglia in a chain along the anterolateral aspect of the vertebral column that are responsible for contributing to homeostatic mechanisms of the autonomic nervous system | ||||
| systemic nerve | nerve in the periphery distal to a nerve plexus or spinal nerve | ||||
| terminal ganglion | autonomic ganglia that are near or within the walls of organs that are responsible for contributing to homeostatic mechanisms of the autonomic nervous system | ||||
| tibial nerve | systemic nerve of the posterior leg that begins as part of the sciatic nerve | ||||
| trigeminal ganglion | sensory ganglion that contributes sensory fibers to the trigeminal nerve | ||||
| trigeminal nerve | fifth cranial nerve; responsible for cutaneous sensation of the face and contraction of the muscles of mastication | ||||
| trochlear nerve | fourth cranial nerve; responsible for contraction of one of the extraocular muscles | ||||
| ulnar nerve | systemic nerve of the arm located close to the ulna, a bone of the forearm | ||||
| vagus nerve | tenth cranial nerve; responsible for the autonomic control of organs in the thoracic and upper abdominal cavities | ||||
| vestibulocochlear nerve | eighth cranial nerve; responsible for the sensations of hearing and balance | ||||
| alkaloid | substance, usually from a plant source, that is chemically basic with respect to pH and will stimulate bitter receptors | ||||
| amacrine cell | type of cell in the retina that connects to the bipolar cells near the outer synaptic layer and provides the basis for early image processing within the retina | ||||
| ampulla | in the ear, the structure at the base of a semicircular canal that contains the hair cells and cupula for transduction of rotational movement of the head | ||||
| anosmia | loss of the sense of smell; usually the result of physical disruption of the first cranial nerve | ||||
| aqueous humor | watery fluid that fills the anterior chamber containing the cornea, iris, ciliary body, and lens of the eye | ||||
| audition | sense of hearing | ||||
| auricle | fleshy external structure of the ear | ||||
| basilar membrane | in the ear, the floor of the cochlear duct on which the organ of Corti sits | ||||
| bipolar cell | cell type in the retina that connects the photoreceptors to the RGCs | ||||
| capsaicin | molecule that activates nociceptors by interacting with a temperature-sensitive ion channel and is the basis for “hot” sensations in spicy food | ||||
| chemoreceptor | sensory receptor cell that is sensitive to chemical stimuli, such as in taste, smell, or pain | ||||
| choroid | highly vascular tissue in the wall of the eye that supplies the outer retina with blood | ||||
| ciliary body | smooth muscle structure on the interior surface of the iris that controls the shape of the lens through the zonule fibers | ||||
| cochlea | auditory portion of the inner ear containing structures to transduce sound stimuli | ||||
| cochlear duct | space within the auditory portion of the inner ear that contains the organ of Corti and is adjacent to the scala tympani and scala vestibuli on either side | ||||
| cone photoreceptor | one of the two types of retinal receptor cell that is specialized for color vision through the use of three photopigments distributed through three separate populations of cells | ||||
| contralateral | word meaning “on the opposite side,” as in axons that cross the midline in a fiber tract | ||||
| cornea | fibrous covering of the anterior region of the eye that is transparent so that light can pass through it | ||||
| cupula | specialized structure within the base of a semicircular canal that bends the stereocilia of hair cells when the head rotates by way of the relative movement of the enclosed fluid | ||||
| encapsulated ending | configuration of a sensory receptor neuron with dendrites surrounded by specialized structures to aid in transduction of a particular type of sensation, such as the lamellated corpuscles in the deep dermis and subcutaneous tissue | ||||
| equilibrium | sense of balance that includes sensations of position and movement of the head | ||||
| external ear | structures on the lateral surface of the head, including the auricle and the ear canal back to the tympanic membrane | ||||
| exteroceptor | sensory receptor that is positioned to interpret stimuli from the external environment, such as photoreceptors in the eye or somatosensory receptors in the skin | ||||
| extraocular muscle | one of six muscles originating out of the bones of the orbit and inserting into the surface of the eye which are responsible for moving the eye | ||||
| fibrous tunic | outer layer of the eye primarily composed of connective tissue known as the sclera and cornea | ||||
| fovea | exact center of the retina at which visual stimuli are focused for maximal acuity, where the retina is thinnest, at which there is nothing but photoreceptors | ||||
| free nerve ending | configuration of a sensory receptor neuron with dendrites in the connective tissue of the organ, such as in the dermis of the skin, that are most often sensitive to chemical, thermal, and mechanical stimuli | ||||
| general sense | any sensory system that is distributed throughout the body and incorporated into organs of multiple other systems, such as the walls of the digestive organs or the skin | ||||
| gustation | sense of taste | ||||
| gustatory receptor cells | sensory cells in the taste bud that transduce the chemical stimuli of gustation | ||||
| hair cells | mechanoreceptor cells found in the inner ear that transduce stimuli for the senses of hearing and balance | ||||
| vertebral arteries | arteries that ascend along either side of the vertebral column through the transverse foramina of the cervical vertebrae and enter the cranium through the foramen magnum | ||||
| incus | (also, anvil) ossicle of the middle ear that connects the malleus to the stapes | ||||
| inferior oblique | extraocular muscle responsible for lateral rotation of the eye | ||||
| inferior rectus | extraocular muscle responsible for looking down | ||||
| inner ear | structure within the temporal bone that contains the sensory apparati of hearing and balance | ||||
| inner segment | in the eye, the section of a photoreceptor that contains the nucleus and other major organelles for normal cellular functions | ||||
| inner synaptic layer | layer in the retina where bipolar cells connect to RGCs | ||||
| interoceptor | sensory receptor that is positioned to interpret stimuli from internal organs, such as stretch receptors in the wall of blood vessels | ||||
| ipsilateral | word meaning on the same side, as in axons that do not cross the midline in a fiber tract | ||||
| iris | colored portion of the anterior eye that surrounds the pupil | ||||
| kinesthesia | sense of body movement based on sensations in skeletal muscles, tendons, joints, and the skin | ||||
| lacrimal duct | duct in the medial corner of the orbit that drains tears into the nasal cavity | ||||
| lacrimal gland | gland lateral to the orbit that produces tears to wash across the surface of the eye | ||||
| lateral rectus | extraocular muscle responsible for abduction of the eye | ||||
| lens | component of the eye that focuses light on the retina | ||||
| levator palpebrae superioris | muscle that causes elevation of the upper eyelid, controlled by fibers in the oculomotor nerve | ||||
| macula | enlargement at the base of a semicircular canal at which transduction of equilibrium stimuli takes place within the ampulla | ||||
| malleus | (also, hammer) ossicle that is directly attached to the tympanic membrane | ||||
| mechanoreceptor | receptor cell that transduces mechanical stimuli into an electrochemical signal | ||||
| medial rectus | extraocular muscle responsible for adduction of the eye | ||||
| middle ear | space within the temporal bone between the ear canal and bony labyrinth where the ossicles amplify sound waves from the tympanic membrane to the oval window | ||||
| neural tunic | layer of the eye that contains nervous tissue, namely the retina | ||||
| nociceptor | receptor cell that senses pain stimuli | ||||
| odorant molecules | volatile chemicals that bind to receptor proteins in olfactory neurons to stimulate the sense of smell | ||||
| olfaction | sense of smell | ||||
| olfactory bulb | central target of the first cranial nerve; located on the ventral surface of the frontal lobe in the cerebrum | ||||
| olfactory epithelium | region of the nasal epithelium where olfactory neurons are located | ||||
| olfactory sensory neuron | receptor cell of the olfactory system, sensitive to the chemical stimuli of smell, the axons of which compose the first cranial nerve | ||||
| opsin | protein that contains the photosensitive cofactor retinal for phototransduction | ||||
| optic disc | spot on the retina at which RGC axons leave the eye and blood vessels of the inner retina pass | ||||
| optic nerve | second cranial nerve, which is responsible visual sensation | ||||
| organ of Corti | structure in the cochlea in which hair cells transduce movements from sound waves into electrochemical signals | ||||
| osmoreceptor | receptor cell that senses differences in the concentrations of bodily fluids on the basis of osmotic pressure | ||||
| ossicles | three small bones in the middle ear | ||||
| otolith | layer of calcium carbonate crystals located on top of the otolithic membrane | ||||
| otolithic membrane | gelatinous substance in the utricle and saccule of the inner ear that contains calcium carbonate crystals and into which the stereocilia of hair cells are embedded | ||||
| outer segment | in the eye, the section of a photoreceptor that contains opsin molecules that transduce light stimuli | ||||
| outer synaptic layer | layer in the retina at which photoreceptors connect to bipolar cells | ||||
| oval window | membrane at the base of the cochlea where the stapes attaches, marking the beginning of the scala vestibuli | ||||
| palpebral conjunctiva | membrane attached to the inner surface of the eyelids that covers the anterior surface of the cornea | ||||
| papilla | for gustation, a bump-like projection on the surface of the tongue that contains taste buds | ||||
| photoisomerization | chemical change in the retinal molecule that alters the bonding so that it switches from the 11-cis-retinal isomer to the all-trans-retinal isomer | ||||
| photon | individual “packet” of light | ||||
| photoreceptor | receptor cell specialized to respond to light stimuli | ||||
| proprioception | sense of position and movement of the body | ||||
| proprioceptor | receptor cell that senses changes in the position and kinesthetic aspects of the body | ||||
| pupil | open hole at the center of the iris that light passes through into the eye | ||||
| receptor cell | cell that transduces environmental stimuli into neural signals | ||||
| retina | nervous tissue of the eye at which phototransduction takes place | ||||
| retinal | cofactor in an opsin molecule that undergoes a biochemical change when struck by a photon (pronounced with a stress on the last syllable) | ||||
| retinal ganglion cell (RGC) | neuron of the retina that projects along the second cranial nerve | ||||
| rhodopsin | photopigment molecule found in the rod photoreceptors | ||||
| rod photoreceptor | one of the two types of retinal receptor cell that is specialized for low-light vision | ||||
| round window | membrane that marks the end of the scala tympani | ||||
| saccule | structure of the inner ear responsible for transducing linear acceleration in the vertical plane | ||||
| scala tympani | portion of the cochlea that extends from the apex to the round window | ||||
| scala vestibuli | portion of the cochlea that extends from the oval window to the apex | ||||
| sclera | white of the eye | ||||
| semicircular canals | structures within the inner ear responsible for transducing rotational movement information | ||||
| sensory modality | a particular system for interpreting and perceiving environmental stimuli by the nervous system | ||||
| somatosensation | general sense associated with modalities lumped together as touch | ||||
| special sense | any sensory system associated with a specific organ structure, namely smell, taste, sight, hearing, and balance | ||||
| spiral ganglion | location of neuronal cell bodies that transmit auditory information along the eighth cranial nerve | ||||
| stapes | (also, stirrup) ossicle of the middle ear that is attached to the inner ear | ||||
| stereocilia | array of apical membrane extensions in a hair cell that transduce movements when they are bent | ||||
| submodality | specific sense within a broader major sense such as sweet as a part of the sense of taste, or color as a part of vision | ||||
| superior oblique | extraocular muscle responsible for medial rotation of the eye | ||||
| superior rectus | extraocular muscle responsible for looking up | ||||
| taste buds | structures within a papilla on the tongue that contain gustatory receptor cells | ||||
| tectorial membrane | component of the organ of Corti that lays over the hair cells, into which the stereocilia are embedded | ||||
| thermoreceptor | sensory receptor specialized for temperature stimuli | ||||
| topographical | relating to positional information | ||||
| transduction | process of changing an environmental stimulus into the electrochemical signals of the nervous system | ||||
| trochlea | cartilaginous structure that acts like a pulley for the superior oblique muscle | ||||
| tympanic membrane | ear drum | ||||
| umami | taste submodality for sensitivity to the concentration of amino acids; also called the savory sense | ||||
| utricle | structure of the inner ear responsible for transducing linear acceleration in the horizontal plane | ||||
| vascular tunic | middle layer of the eye primarily composed of connective tissue with a rich blood supply | ||||
| vestibular ganglion | location of neuronal cell bodies that transmit equilibrium information along the eighth cranial nerve | ||||
| vestibule | in the ear, the portion of the inner ear responsible for the sense of equilibrium | ||||
| visceral sense | sense associated with the internal organs | ||||
| vision | special sense of sight based on transduction of light stimuli | ||||
| visual acuity | property of vision related to the sharpness of focus, which varies in relation to retinal position | ||||
| vitreous humor | viscous fluid that fills the posterior chamber of the eye | ||||
| zonule fibers | fibrous connections between the ciliary body and the lens | ||||
| ascending pathway | fiber structure that relays sensory information from the periphery through the spinal cord and brain stem to other structures of the brain | ||||
| association area | region of cortex connected to a primary sensory cortical area that further processes the information to generate more complex sensory perceptions | ||||
| binocular depth cues | indications of the distance of visual stimuli on the basis of slight differences in the images projected onto either retina | ||||
| chief sensory nucleus | component of the trigeminal nuclei that is found in the pons | ||||
| circadian rhythm | internal perception of the daily cycle of light and dark based on retinal activity related to sunlight | ||||
| decussate | to cross the midline, as in fibers that project from one side of the body to the other | ||||
| dorsal column system | ascending tract of the spinal cord associated with fine touch and proprioceptive sensations | ||||
| dorsal stream | connections between cortical areas from the occipital to parietal lobes that are responsible for the perception of visual motion and guiding movement of the body in relation to that motion | ||||
| fasciculus cuneatus | lateral division of the dorsal column system composed of fibers from sensory neurons in the upper body | ||||
| fasciculus gracilis | medial division of the dorsal column system composed of fibers from sensory neurons in the lower body | ||||
| inferior colliculus | last structure in the auditory brainstem pathway that projects to the thalamus and superior colliculus | ||||
| interaural intensity difference | cue used to aid sound localization in the horizontal plane that compares the relative loudness of sounds at the two ears, because the ear closer to the sound source will hear a slightly more intense sound | ||||
| interaural time difference | cue used to help with sound localization in the horizontal plane that compares the relative time of arrival of sounds at the two ears, because the ear closer to the sound source will receive the stimulus microseconds before the other ear | ||||
| lateral geniculate nucleus | thalamic target of the RGCs that projects to the visual cortex | ||||
| medial geniculate nucleus | thalamic target of the auditory brain stem that projects to the auditory cortex | ||||
| medial lemniscus | fiber tract of the dorsal column system that extends from the nuclei gracilis and cuneatus to the thalamus, and decussates | ||||
| mesencephalic nucleus | component of the trigeminal nuclei that is found in the midbrain | ||||
| multimodal integration area | region of the cerebral cortex in which information from more than one sensory modality is processed to arrive at higher level cortical functions such as memory, learning, or cognition | ||||
| nucleus cuneatus | medullary nucleus at which first-order neurons of the dorsal column system synapse specifically from the upper body and arms | ||||
| nucleus gracilis | medullary nucleus at which first-order neurons of the dorsal column system synapse specifically from the lower body and legs | ||||
| optic chiasm | decussation point in the visual system at which medial retina fibers cross to the other side of the brain | ||||
| optic tract | name for the fiber structure containing axons from the retina posterior to the optic chiasm representing their CNS location | ||||
| primary sensory cortex | region of the cerebral cortex that initially receives sensory input from an ascending pathway from the thalamus and begins the processing that will result in conscious perception of that modality | ||||
| sensory homunculus | topographic representation of the body within the somatosensory cortex demonstrating the correspondence between neurons processing stimuli and sensitivity | ||||
| solitary nucleus | medullar nucleus that receives taste information from the facial and glossopharyngeal nerves | ||||
| spinal trigeminal nucleus | component of the trigeminal nuclei that is found in the medulla | ||||
| spinothalamic tract | ascending tract of the spinal cord associated with pain and temperature sensations | ||||
| superior colliculus | structure in the midbrain that combines visual, auditory, and somatosensory input to coordinate spatial and topographic representations of the three sensory systems | ||||
| suprachiasmatic nucleus | hypothalamic target of the retina that helps to establish the circadian rhythm of the body on the basis of the presence or absence of daylight | ||||
| ventral posterior nucleus | nucleus in the thalamus that is the target of gustatory sensations and projects to the cerebral cortex | ||||
| ventral stream | connections between cortical areas from the occipital lobe to the temporal lobe that are responsible for identification of visual stimuli | ||||
| vestibular nuclei | targets of the vestibular component of the eighth cranial nerve | ||||
| vestibulo-ocular reflex (VOR) | reflex based on connections between the vestibular system and the cranial nerves of eye movements that ensures images are stabilized on the retina as the head and body move | ||||
| anterior corticospinal tract | division of the corticospinal pathway that travels through the ventral (anterior) column of the spinal cord and controls axial musculature through the medial motor neurons in the ventral (anterior) horn | ||||
| Betz cells | output cells of the primary motor cortex that cause musculature to move through synapses on cranial and spinal motor neurons | ||||
| Broca’s area | region of the frontal lobe associated with the motor commands necessary for speech production | ||||
| cerebral peduncles | segments of the descending motor pathway that make up the white matter of the ventral midbrain | ||||
| cervical enlargement | region of the ventral (anterior) horn of the spinal cord that has a larger population of motor neurons for the greater number of and finer control of muscles of the upper limb | ||||
| corneal reflex | protective response to stimulation of the cornea causing contraction of the orbicularis oculi muscle resulting in blinking of the eye | ||||
| corticobulbar tract | connection between the cortex and the brain stem responsible for generating movement | ||||
| corticospinal tract | connection between the cortex and the spinal cord responsible for generating movement | ||||
| executive functions | cognitive processes of the prefrontal cortex that lead to directing goal-directed behavior, which is a precursor to executing motor commands | ||||
| extrapyramidal system | pathways between the brain and spinal cord that are separate from the corticospinal tract and are responsible for modulating the movements generated through that primary pathway | ||||
| frontal eye fields | area of the prefrontal cortex responsible for moving the eyes to attend to visual stimuli | ||||
| internal capsule | segment of the descending motor pathway that passes between the caudate nucleus and the putamen | ||||
| lateral corticospinal tract | division of the corticospinal pathway that travels through the lateral column of the spinal cord and controls appendicular musculature through the lateral motor neurons in the ventral (anterior) horn | ||||
| lumbar enlargement | region of the ventral (anterior) horn of the spinal cord that has a larger population of motor neurons for the greater number of muscles of the lower limb | ||||
| premotor cortex | cortical area anterior to the primary motor cortex that is responsible for planning movements | ||||
| pyramidal decussation | location at which corticospinal tract fibers cross the midline and segregate into the anterior and lateral divisions of the pathway | ||||
| pyramids | segment of the descending motor pathway that travels in the anterior position of the medulla | ||||
| red nucleus | midbrain nucleus that sends corrective commands to the spinal cord along the rubrospinal tract, based on disparity between an original command and the sensory feedback from movement | ||||
| reticulospinal tract | extrapyramidal connections between the brain stem and spinal cord that modulate movement, contribute to posture, and regulate muscle tone | ||||
| rubrospinal tract | descending motor control pathway, originating in the red nucleus, that mediates control of the limbs on the basis of cerebellar processing | ||||
| stretch reflex | response to activation of the muscle spindle stretch receptor that causes contraction of the muscle to maintain a constant length | ||||
| supplemental motor area | cortical area anterior to the primary motor cortex that is responsible for planning movements | ||||
| tectospinal tract | extrapyramidal connections between the superior colliculus and spinal cord | ||||
| vestibulospinal tract | extrapyramidal connections between the vestibular nuclei in the brain stem and spinal cord that modulate movement and contribute to balance on the basis of the sense of equilibrium | ||||
| working memory | function of the prefrontal cortex to maintain a representation of information that is not in the immediate environment | ||||
| alpha (α)-adrenergic receptor | one of the receptors to which epinephrine and norepinephrine bind, which comes in three subtypes: α1, α2, and α3 | ||||
| acetylcholine (ACh) | neurotransmitter that binds at a motor end-plate to trigger depolarization | ||||
| adrenal medulla | interior portion of the adrenal (or suprarenal) gland that releases epinephrine and norepinephrine into the bloodstream as hormones | ||||
| adrenergic | synapse where norepinephrine is released, which binds to α- or β-adrenergic receptors | ||||
| beta (β)-adrenergic receptor | one of the receptors to which epinephrine and norepinephrine bind, which comes in two subtypes: β1 and β2 | ||||
| celiac ganglion | one of the collateral ganglia of the sympathetic system that projects to the digestive system | ||||
| central neuron | specifically referring to the cell body of a neuron in the autonomic system that is located in the central nervous system, specifically the lateral horn of the spinal cord or a brain stem nucleus | ||||
| cholinergic | synapse at which acetylcholine is released and binds to the nicotinic or muscarinic receptor | ||||
| chromaffin cells | neuroendocrine cells of the adrenal medulla that release epinephrine and norepinephrine into the bloodstream as part of sympathetic system activity | ||||
| ciliary ganglion | one of the terminal ganglia of the parasympathetic system, located in the posterior orbit, axons from which project to the iris | ||||
| collateral ganglia | ganglia outside of the sympathetic chain that are targets of sympathetic preganglionic fibers, which are the celiac, inferior mesenteric, and superior mesenteric ganglia | ||||
| craniosacral system | alternate name for the parasympathetic division of the autonomic nervous system that is based on the anatomical location of central neurons in brain-stem nuclei and the lateral horn of the sacral spinal cord; also referred to as craniosacral outflow | ||||
| dorsal nucleus of the vagus nerve | location of parasympathetic neurons that project through the vagus nerve to terminal ganglia in the thoracic and abdominal cavities | ||||
| Eddinger–Westphal nucleus | location of parasympathetic neurons that project to the ciliary ganglion | ||||
| endogenous | describes substance made in the human body | ||||
| epinephrine | signaling molecule released from the adrenal medulla into the bloodstream as part of the sympathetic response | ||||
| exogenous | describes substance made outside of the human body | ||||
| fight-or-flight response | set of responses induced by sympathetic activity that lead to either fleeing a threat or standing up to it, which in the modern world is often associated with anxious feelings | ||||
| G protein–coupled receptor | membrane protein complex that consists of a receptor protein that binds to a signaling molecule—a G protein—that is activated by that binding and in turn activates an effector protein (enzyme) that creates a second-messenger molecule in the cytoplasm of the target cell | ||||
| ganglionic neuron | specifically refers to the cell body of a neuron in the autonomic system that is located in a ganglion | ||||
| gray rami communicantes | (singular = ramus communicans) unmyelinated structures that provide a short connection from a sympathetic chain ganglion to the spinal nerve that contains the postganglionic sympathetic fiber | ||||
| greater splanchnic nerve | nerve that contains fibers of the central sympathetic neurons that do not synapse in the chain ganglia but project onto the celiac ganglion | ||||
| inferior mesenteric ganglion | one of the collateral ganglia of the sympathetic system that projects to the digestive system | ||||
| intramural ganglia | terminal ganglia of the parasympathetic system that are found within the walls of the target effector | ||||
| lesser splanchnic nerve | nerve that contains fibers of the central sympathetic neurons that do not synapse in the chain ganglia but project onto the inferior mesenteric ganglion | ||||
| ligand-gated cation channel | ion channel, such as the nicotinic receptor, that is specific to positively charged ions and opens when a molecule such as a neurotransmitter binds to it | ||||
| mesenteric plexus | nervous tissue within the wall of the digestive tract that contains neurons that are the targets of autonomic preganglionic fibers and that project to the smooth muscle and glandular tissues in the digestive organ | ||||
| muscarinic receptor | type of acetylcholine receptor protein that is characterized by also binding to muscarine and is a metabotropic receptor | ||||
| nicotinic receptor | type of acetylcholine receptor protein that is characterized by also binding to nicotine and is an ionotropic receptor | ||||
| norepinephrine | signaling molecule released as a neurotransmitter by most postganglionic sympathetic fibers as part of the sympathetic response, or as a hormone into the bloodstream from the adrenal medulla | ||||
| nucleus ambiguus | brain-stem nucleus that contains neurons that project through the vagus nerve to terminal ganglia in the thoracic cavity; specifically associated with the heart | ||||
| parasympathetic division | division of the autonomic nervous system responsible for restful and digestive functions | ||||
| paravertebral ganglia | autonomic ganglia superior to the sympathetic chain ganglia | ||||
| postganglionic fiber | axon from a ganglionic neuron in the autonomic nervous system that projects to and synapses with the target effector; sometimes referred to as a postganglionic neuron | ||||
| preganglionic fiber | axon from a central neuron in the autonomic nervous system that projects to and synapses with a ganglionic neuron; sometimes referred to as a preganglionic neuron | ||||
| prevertebral ganglia | autonomic ganglia that are anterior to the vertebral column and functionally related to the sympathetic chain ganglia | ||||
| rest and digest | set of functions associated with the parasympathetic system that lead to restful actions and digestion | ||||
| superior cervical ganglion | one of the paravertebral ganglia of the sympathetic system that projects to the head | ||||
| superior mesenteric ganglion | one of the collateral ganglia of the sympathetic system that projects to the digestive system | ||||
| sympathetic chain ganglia | series of ganglia adjacent to the vertebral column that receive input from central sympathetic neurons | ||||
| sympathetic division | division of the autonomic nervous system associated with the fight-or-flight response | ||||
| target effector | organ, tissue, or gland that will respond to the control of an autonomic or somatic or endocrine signal | ||||
| terminal ganglia | ganglia of the parasympathetic division of the autonomic system, which are located near or within the target effector, the latter also known as intramural ganglia | ||||
| thoracolumbar system | alternate name for the sympathetic division of the autonomic nervous system that is based on the anatomical location of central neurons in the lateral horn of the thoracic and upper lumbar spinal cord | ||||
| varicosity | structure of some autonomic connections that is not a typical synaptic end bulb, but a string of swellings along the length of a fiber that makes a network of connections with the target effector | ||||
| white rami communicantes | (singular = ramus communicans) myelinated structures that provide a short connection from a sympathetic chain ganglion to the spinal nerve that contains the preganglionic sympathetic fiber | ||||
| autonomic tone | tendency of an organ system to be governed by one division of the autonomic nervous system over the other, such as heart rate being lowered by parasympathetic input at rest | ||||
| afferent branch | component of a reflex arc that represents the input from a sensory neuron, for either a special or general sense | ||||
| baroreceptor | mechanoreceptor that senses the stretch of blood vessels to indicate changes in blood pressure | ||||
| efferent branch | component of a reflex arc that represents the output, with the target being an effector, such as muscle or glandular tissue | ||||
| long reflex | reflex arc that includes the central nervous system | ||||
| referred pain | the conscious perception of visceral sensation projected to a different region of the body, such as the left shoulder and arm pain as a sign for a heart attack | ||||
| reflex arc | circuit of a reflex that involves a sensory input and motor output, or an afferent branch and an efferent branch, and an integrating center to connect the two branches | ||||
| short reflex | reflex arc that does not include any components of the central nervous system | ||||
| somatic reflex | reflex involving skeletal muscle as the effector, under the control of the somatic nervous system | ||||
| visceral reflex | reflex involving an internal organ as the effector, under the control of the autonomic nervous system | ||||
| cardiac accelerator nerves | preganglionic sympathetic fibers that cause the heart rate to increase when the cardiovascular center in the medulla initiates a signal | ||||
| cardiovascular center | region in the medulla that controls the cardiovascular system through cardiac accelerator nerves and vasomotor nerves, which are components of the sympathetic division of the autonomic nervous system | ||||
| dorsal longitudinal fasciculus | major output pathway of the hypothalamus that descends through the gray matter of the brain stem and into the spinal cord | ||||
| limbic lobe | structures arranged around the edges of the cerebrum that are involved in memory and emotion | ||||
| medial forebrain bundle | fiber pathway that extends anteriorly into the basal forebrain, passes through the hypothalamus, and extends into the brain stem and spinal cord | ||||
| vasomotor nerves | preganglionic sympathetic fibers that cause the constriction of blood vessels in response to signals from the cardiovascular center | ||||
| autocrine | chemical signal that elicits a response in the same cell that secreted it | ||||
| endocrine gland | tissue or organ that secretes hormones into the blood and lymph without ducts such that they may be transported to organs distant from the site of secretion | ||||
| endocrine system | cells, tissues, and organs that secrete hormones as a primary or secondary function and play an integral role in normal bodily processes | ||||
| exocrine system | cells, tissues, and organs that secrete substances directly to target tissues via glandular ducts | ||||
| hormone receptor | protein within a cell or on the cell membrane that binds a hormone, initiating the target cell response | ||||
| hormone | secretion of an endocrine organ that travels via the bloodstream or lymphatics to induce a response in target cells or tissues in another part of the body | ||||
| humoral stimuli | changes in blood levels of non-hormone chemicals such as ions or nutrients that cause release or inhibition of a hormone to maintain homeostasis of the chemical | ||||
| negative feedback loop | type of regulation in which increasing levels of a substance signal that the substance no longer needs to be released, resulting in lowered levels of the substance | ||||
| paracrine | chemical signal that elicits a response in neighboring cells; also called paracrine factor | ||||
| adrenocorticotropic hormone (ACTH) | anterior pituitary hormone that stimulates the adrenal cortex to secrete corticosteroid hormones (also called corticotropin) | ||||
| antidiuretic hormone (ADH) | hypothalamic hormone that is stored by the posterior pituitary and that signals the kidneys to reabsorb water | ||||
| follicle-stimulating hormone (FSH) | anterior pituitary hormone that stimulates the production and maturation of sex cells | ||||
| gonadotropins | hormones that regulate the function of the gonads | ||||
| growth hormone (GH) | anterior pituitary hormone that promotes tissue building and influences nutrient metabolism (also called somatotropin) | ||||
| hypophyseal portal system | network of blood vessels that enables hypothalamic hormones to travel into the anterior lobe of the pituitary without entering the systemic circulation | ||||
| hypothalamus | region of the diencephalon inferior to the thalamus that functions in neural and endocrine signaling | ||||
| infundibulum | stalk containing vasculature and neural tissue that connects the pituitary gland to the hypothalamus (also called the pituitary stalk) | ||||
| insulin-like growth factors (IGF) | protein that enhances cellular proliferation, inhibits apoptosis, and stimulates the cellular uptake of amino acids for protein synthesis | ||||
| luteinizing hormone (LH) | anterior pituitary hormone that triggers ovulation and the production of ovarian hormones in females, and the production of testosterone in males | ||||
| osmoreceptor | hypothalamic sensory receptor that is stimulated by changes in solute concentration (osmotic pressure) in the blood | ||||
| oxytocin | hypothalamic hormone stored in the posterior pituitary gland and important in stimulating uterine contractions in labor, milk ejection during breastfeeding, and feelings of attachment (also produced in males) | ||||
| pituitary gland | bean-sized organ suspended from the hypothalamus that produces, stores, and secretes hormones in response to hypothalamic stimulation (also called hypophysis) | ||||
| prolactin (PRL) | anterior pituitary hormone that promotes development of the mammary glands and the production of breast milk | ||||
| thyroid-stimulating hormone (TSH) | anterior pituitary hormone that triggers secretion of thyroid hormones by the thyroid gland (also called thyrotropin) | ||||
| calcitonin | peptide hormone produced and secreted by the parafollicular cells (C cells) of the thyroid gland that functions to decrease blood calcium levels | ||||
| colloid | viscous fluid in the central cavity of thyroid follicles, containing the glycoprotein thyroglobulin | ||||
| goiter | enlargement of the thyroid gland either as a result of iodine deficiency or hyperthyroidism | ||||
| hyperthyroidism | clinically abnormal, elevated level of thyroid hormone in the blood; characterized by an increased metabolic rate, excess body heat, sweating, diarrhea, weight loss, and increased heart rate | ||||
| hypothyroidism | clinically abnormal, low level of thyroid hormone in the blood; characterized by low metabolic rate, weight gain, cold extremities, constipation, and reduced mental activity | ||||
| neonatal hypothyroidism | condition characterized by cognitive deficits, short stature, and other signs and symptoms in people born to women who were iodine-deficient during pregnancy | ||||
| thyroid gland | large endocrine gland responsible for the synthesis of thyroid hormones | ||||
| thyroxine | (also, tetraiodothyronine, T4) amino acid–derived thyroid hormone that is more abundant but less potent than T3 and often converted to T3 by target cells | ||||
| triiodothyronine | (also, T3) amino acid–derived thyroid hormone that is less abundant but more potent than T4 | ||||
| hyperparathyroidism | disorder caused by overproduction of PTH that results in abnormally elevated blood calcium | ||||
| hypoparathyroidism | disorder caused by underproduction of PTH that results in abnormally low blood calcium | ||||
| parathyroid glands | small, round glands embedded in the posterior thyroid gland that produce parathyroid hormone (PTH) | ||||
| parathyroid hormone (PTH) | peptide hormone produced and secreted by the parathyroid glands in response to low blood calcium levels | ||||
| adrenal cortex | outer region of the adrenal glands consisting of multiple layers of epithelial cells and capillary networks that produces mineralocorticoids and glucocorticoids | ||||
| adrenal glands | endocrine glands located at the top of each kidney that are important for the regulation of the stress response, blood pressure and blood volume, water homeostasis, and electrolyte levels | ||||
| adrenal medulla | inner layer of the adrenal glands that plays an important role in the stress response by producing epinephrine and norepinephrine | ||||
| angiotensin-converting enzyme | the enzyme that converts angiotensin I to angiotensin II | ||||
| alarm reaction | the short-term stress, or the fight-or-flight response, of stage one of the general adaptation syndrome mediated by the hormones epinephrine and norepinephrine | ||||
| aldosterone | hormone produced and secreted by the adrenal cortex that stimulates sodium and fluid retention and increases blood volume and blood pressure | ||||
| chromaffin | neuroendocrine cells of the adrenal medulla | ||||
| cortisol | glucocorticoid important in gluconeogenesis, the catabolism of glycogen, and downregulation of the immune system | ||||
| epinephrine | primary and most potent catecholamine hormone secreted by the adrenal medulla in response to short-term stress; also called adrenaline | ||||
| general adaptation syndrome (GAS) | the human body’s three-stage response pattern to short- and long-term stress | ||||
| glucocorticoids | hormones produced by the zona fasciculata of the adrenal cortex that influence glucose metabolism | ||||
| mineralocorticoids | hormones produced by the zona glomerulosa cells of the adrenal cortex that influence fluid and electrolyte balance | ||||
| norepinephrine | secondary catecholamine hormone secreted by the adrenal medulla in response to short-term stress; also called noradrenaline | ||||
| stage of exhaustion | stage three of the general adaptation syndrome; the body’s long-term response to stress mediated by the hormones of the adrenal cortex | ||||
| stage of resistance | stage two of the general adaptation syndrome; the body’s continued response to stress after stage one diminishes | ||||
| zona fasciculata | intermediate region of the adrenal cortex that produce hormones called glucocorticoids | ||||
| zona glomerulosa | most superficial region of the adrenal cortex, which produces the hormones collectively referred to as mineralocorticoids | ||||
| zona reticularis | deepest region of the adrenal cortex, which produces the steroid sex hormones called androgens | ||||
| melatonin | amino acid–derived hormone that is secreted in response to low light and causes drowsiness | ||||
| pineal gland | endocrine gland that secretes melatonin, which is important in regulating the sleep-wake cycle | ||||
| pinealocyte | cell of the pineal gland that produces and secretes the hormone melatonin | ||||
| estrogens | class of predominantly female sex hormones important for the development and growth of the female reproductive tract, secondary sex characteristics, the female reproductive cycle, and the maintenance of pregnancy | ||||
| inhibin | hormone secreted by the male and female gonads that inhibits FSH production by the anterior pituitary | ||||
| progesterone | predominantly female sex hormone important in regulating the female reproductive cycle and the maintenance of pregnancy | ||||
| testosterone | steroid hormone secreted by the male testes and important in the maturation of sperm cells, growth and development of the male reproductive system, and the development of male secondary sex characteristics | ||||
| alpha cell | pancreatic islet cell type that produces the hormone glucagon | ||||
| beta cell | pancreatic islet cell type that produces the hormone insulin | ||||
| delta cell | minor cell type in the pancreas that secretes the hormone somatostatin | ||||
| diabetes mellitus | condition caused by destruction or dysfunction of the beta cells of the pancreas or cellular resistance to insulin that results in abnormally high blood glucose levels | ||||
| glucagon | pancreatic hormone that stimulates the catabolism of glycogen to glucose, thereby increasing blood glucose levels | ||||
| hyperglycemia | abnormally high blood glucose levels | ||||
| insulin | pancreatic hormone that enhances the cellular uptake and utilization of glucose, thereby decreasing blood glucose levels | ||||
| pancreas | organ with both exocrine and endocrine functions located posterior to the stomach that is important for digestion and the regulation of blood glucose | ||||
| pancreatic islets | specialized clusters of pancreatic cells that have endocrine functions; also called islets of Langerhans | ||||
| PP cell | minor cell type in the pancreas that secretes the hormone pancreatic polypeptide | ||||
| atrial natriuretic peptide (ANP) | hormone secreted by the atria of the heart to signal for a reduction in blood volume, blood pressure, and blood sodium levels | ||||
| erythropoietin (EPO) | hormone secreted by the kidney to stimulate production of red blood cells in order to increase blood oxygen levels | ||||
| leptin | protein hormone secreted by adipose tissues in response to food consumption that promotes satiety | ||||
| albumin | most abundant plasma protein, accounting for most of the osmotic pressure of plasma | ||||
| antibodies | (also, immunoglobulins or gamma globulins) antigen-specific proteins produced by specialized B lymphocytes that protect the body by binding to foreign objects such as bacteria and viruses | ||||
| blood | liquid connective tissue composed of formed elements—erythrocytes, leukocytes, and platelets—and a fluid extracellular matrix called plasma; component of the cardiovascular system | ||||
| buffy coat | thin, pale layer of leukocytes and platelets that separates the erythrocytes from the plasma in a sample of centrifuged blood | ||||
| complete blood count (CBC) with differential | a test in which a prepared microscope slide of a patient's blood is used to count the numbers of each type of formed element visible in a given volume of blood; observations about the size, shape, and characteristics of each type of formed element are also made | ||||
| fibrinogen | plasma protein produced in the liver and involved in blood clotting | ||||
| formed elements | cellular components of blood; that is, erythrocytes, leukocytes, and platelets | ||||
| globulins | heterogeneous group of plasma proteins that includes transport proteins, clotting factors, immune proteins, and others | ||||
| hematocrit | (also, packed cell volume) volume percentage of erythrocytes in a sample of centrifuged blood | ||||
| immunoglobulins | (also, antibodies or gamma globulins) antigen-specific proteins produced by specialized B lymphocytes that protect the body by binding to foreign objects such as bacteria and viruses | ||||
| packed cell volume (PCV) | (also, hematocrit) volume percentage of erythrocytes present in a sample of centrifuged blood | ||||
| plasma | in blood, the liquid extracellular matrix composed mostly of water that circulates the formed elements and dissolved materials throughout the cardiovascular system | ||||
| platelets | (also, thrombocytes) one of the formed elements of blood that consists of cell fragments broken off from megakaryocytes | ||||
| red blood cells (RBCs) | (also, erythrocytes) one of the formed elements of blood that transports oxygen | ||||
| anemia | deficiency of red blood cells or hemoglobin | ||||
| bilirubin | yellowish bile pigment produced when iron is removed from heme and is further broken down into waste products | ||||
| biliverdin | green bile pigment produced when the non-iron portion of heme is degraded into a waste product; converted to bilirubin in the liver | ||||
| carbaminohemoglobin | compound of carbon dioxide and hemoglobin, and one of the ways in which carbon dioxide is carried in the blood | ||||
| deoxyhemoglobin | molecule of hemoglobin without an oxygen molecule bound to it | ||||
| erythrocyte | (also, red blood cell) mature myeloid blood cell that is composed mostly of hemoglobin and functions primarily in the transportation of oxygen and carbon dioxide | ||||
| globin | heme-containing globular protein that is a constituent of hemoglobin | ||||
| heme | red, iron-containing pigment to which oxygen binds in hemoglobin | ||||
| hemoglobin | oxygen-carrying compound in erythrocytes | ||||
| hypoxemia | below-normal level of oxygen saturation of blood (typically <95 percent) | ||||
| macrophage | phagocytic cell of the myeloid lineage; a matured monocyte | ||||
| oxyhemoglobin | molecule of hemoglobin to which oxygen is bound | ||||
| polycythemia | elevated level of hemoglobin, whether adaptive or pathological | ||||
| reticulocyte | immature erythrocyte that may still contain fragments of organelles | ||||
| sickle cell disease | (also, sickle cell anemia) inherited blood disorder in which hemoglobin molecules are malformed, leading to the breakdown of RBCs that take on a characteristic sickle shape | ||||
| thalassemia | inherited blood disorder in which maturation of RBCs does not proceed normally, leading to abnormal formation of hemoglobin and the destruction of RBCs | ||||
| agranular leukocytes | leukocytes with few granules in their cytoplasm; specifically, monocytes, lymphocytes, and NK cells | ||||
| B lymphocytes | (also, B cells) lymphocytes that defend the body against specific pathogens and thereby provide specific immunity | ||||
| basophils | granulocytes that stain with a basic (alkaline) stain and store histamine and heparin | ||||
| blood clot | mesh of fibrin proteins and sticky platelets and red blood cells that forms a more durable and long-lasting seal for a damaged blood vessel wall during hemostasis | ||||
| coagulation | process of forming a blood clot during hemostasis | ||||
| defensins | antimicrobial proteins released from neutrophils and macrophages that create openings in the plasma membranes to kill cells | ||||
| diapedesis | (also, emigration) process by which leukocytes squeeze through adjacent cells in a blood vessel wall to enter tissues | ||||
| emigration | (also, diapedesis) process by which leukocytes squeeze through adjacent cells in a blood vessel wall to enter tissues | ||||
| eosinophils | granulocytes that stain with eosin; they release antihistamines and are especially active against parasitic worms | ||||
| fibrin | activated form of the plasma protein fibrinogen; elongated, fibrous protein that forms a mesh framework within a blood clot | ||||
| granular leukocytes | leukocytes with abundant granules in their cytoplasm; specifically, neutrophils, eosinophils, and basophils | ||||
| hemophilia | a group of genetic disorders that can result in excessive bleeding related to inadequate production of one or more clotting factors | ||||
| hemostasis | stoppage of blood flow following damage to a vessel | ||||
| leukemia | cancer involving leukocytes | ||||
| leukocyte | (also, white blood cell) colorless, nucleated blood cell, the chief function of which is to protect the body from disease | ||||
| leukocytosis | excessive leukocyte proliferation | ||||
| leukopenia | below-normal production of leukocytes | ||||
| lymphocytes | agranular leukocytes of the lymphoid stem cell line, many of which function in specific immunity | ||||
| lymphoma | form of cancer in which masses of malignant T and/or B lymphocytes collect in lymph nodes, the spleen, the liver, and other tissues | ||||
| lysozyme | digestive enzyme with bactericidal properties | ||||
| megakaryocyte | bone marrow cell that produces platelets | ||||
| memory cell | type of B or T lymphocyte that forms after exposure to a pathogen | ||||
| monocytes | agranular leukocytes of the myeloid stem cell line that circulate in the bloodstream; tissue monocytes are macrophages | ||||
| natural killer (NK) cells | cytotoxic lymphocytes capable of recognizing cells that do not express “self” proteins on their plasma membrane or that contain foreign or abnormal markers; provide generalized, nonspecific immunity | ||||
| neutrophils | granulocytes that stain with a neutral dye and are the most numerous of the leukocytes; especially active against bacteria | ||||
| platelet plug | temporary seal for a damaged blood vessel wall during hemostasis; comprised of sticky platelets attached to the damaged vessel wall | ||||
| polymorphonuclear | having a lobed nucleus, as seen in some leukocytes | ||||
| positive chemotaxis | process in which a cell is attracted to move in the direction of chemical stimuli | ||||
| T lymphocytes | (also, T cells) lymphocytes that provide cellular-level immunity by physically attacking foreign or diseased cells | ||||
| thrombocytes | platelets, one of the formed elements of blood that consists of cell fragments broken off from megakaryocytes | ||||
| thrombocytopenia | condition in which there are too few platelets, resulting in abnormal bleeding (hemophilia) | ||||
| thrombocytosis | condition in which there are too many platelets, resulting in abnormal clotting (thrombosis) | ||||
| bone marrow biopsy | diagnostic test of a sample of red bone marrow | ||||
| bone marrow transplant | treatment in which a donor’s healthy bone marrow with its stem cells replaces diseased or damaged bone marrow of a patient | ||||
| colony-stimulating factors (CSFs) | glycoproteins that trigger the proliferation and differentiation of myeloblasts into granular leukocytes (basophils, neutrophils, and eosinophils) | ||||
| cytokines | class of protein signaling molecules; in the cardiovascular system, they stimulate the proliferation of progenitor cells and help to stimulate both nonspecific and specific resistance to disease | ||||
| erythropoietin (EPO) | glycoprotein that triggers the bone marrow to produce RBCs; secreted by the kidney in response to low oxygen levels | ||||
| hemocytoblast | hemopoietic stem cell that gives rise to the formed elements of blood | ||||
| hemopoiesis | production of the formed elements of blood | ||||
| hemopoietic growth factors | chemical signals including erythropoietin, thrombopoietin, colony-stimulating factors, and interleukins that regulate the differentiation and proliferation of particular blood progenitor cells | ||||
| hemopoietic stem cell | type of pluripotent stem cell that gives rise to the formed elements of blood (hemocytoblast) | ||||
| interleukins | signaling molecules that may function in hemopoiesis, inflammation, and specific immune responses | ||||
| lymphoid stem cells | type of hemopoietic stem cells that gives rise to lymphocytes, including various T cells, B cells, and NK cells, all of which function in immunity | ||||
| myeloid stem cells | type of hemopoietic stem cell that gives rise to some formed elements, including erythrocytes, megakaryocytes that produce platelets, and a myeloblast lineage that gives rise to monocytes and three forms of granular leukocytes (neutrophils, eosinophils, and basophils) | ||||
| pluripotent stem cell | stem cell that derives from totipotent stem cells and is capable of differentiating into many, but not all, cell types | ||||
| totipotent stem cell | embryonic stem cell that is capable of differentiating into any and all cells of the body; enabling the full development of an organism | ||||
| thrombopoietin | hormone secreted by the liver and kidneys that prompts the development of megakaryocytes into thrombocytes (platelets) | ||||
| ABO blood group | blood-type classification based on the presence or absence of A and B glycoproteins on the erythrocyte membrane surface | ||||
| agglutination | clustering of cells into masses linked by antibodies | ||||
| cross matching | blood test for identification of blood type using antibodies and small samples of blood | ||||
| hemolysis | destruction (lysis) of erythrocytes and the release of their hemoglobin into circulation | ||||
| hemolytic disease of the newborn (HDN) | (also, erythroblastosis fetalis) disorder causing agglutination and hemolysis in an Rh+ fetus or newborn of an Rh− mother | ||||
| Rh blood group | blood-type classification based on the presence or absence of the antigen Rh on the erythrocyte membrane surface | ||||
| universal donor | individual with type O− blood | ||||
| universal recipient | individual with type AB+ blood | ||||
| anastomosis | (plural = anastomoses) area where vessels unite to allow blood to circulate even if there may be partial blockage in another branch | ||||
| anterior cardiac veins | vessels that parallel the small cardiac arteries and drain the anterior surface of the right ventricle; bypass the coronary sinus and drain directly into the right atrium | ||||
| anterior interventricular artery | (also, left anterior descending artery or LAD) major branch of the left coronary artery that follows the anterior interventricular sulcus | ||||
| anterior interventricular sulcus | sulcus located between the left and right ventricles on the anterior surface of the heart | ||||
| aortic valve | (also, aortic semilunar valve) valve located at the base of the aorta | ||||
| atrioventricular septum | cardiac septum located between the atria and ventricles; atrioventricular valves are located here | ||||
| atrioventricular valves | one-way valves located between the atria and ventricles; the valve on the right is called the tricuspid valve, and the one on the left is the mitral or bicuspid valve | ||||
| atrium | (plural = atria) upper or receiving chamber of the heart that pumps blood into the lower chambers just prior to their contraction; the right atrium receives blood from the systemic circuit that flows into the right ventricle; the left atrium receives blood from the pulmonary circuit that flows into the left ventricle | ||||
| auricle | extension of an atrium visible on the superior surface of the heart | ||||
| bicuspid valve | (also, mitral valve or left atrioventricular valve) valve located between the left atrium and ventricle; consists of two flaps of tissue | ||||
| cardiac notch | depression in the medial surface of the inferior lobe of the left lung where the apex of the heart is located | ||||
| cardiac skeleton | (also, skeleton of the heart) reinforced connective tissue located within the atrioventricular septum; includes four rings that surround the openings between the atria and ventricles, and the openings to the pulmonary trunk and aorta; the point of attachment for the heart valves | ||||
| cardiomyocyte | muscle cell of the heart | ||||
| chordae tendineae | string-like extensions of tough connective tissue that extend from the flaps of the atrioventricular valves to the papillary muscles | ||||
| circumflex artery | branch of the left coronary artery that follows coronary sulcus | ||||
| coronary arteries | branches of the ascending aorta that supply blood to the heart; the left coronary artery feeds the left side of the heart, the left atrium and ventricle, and the interventricular septum; the right coronary artery feeds the right atrium, portions of both ventricles, and the heart conduction system | ||||
| coronary sinus | large, thin-walled vein on the posterior surface of the heart that lies within the atrioventricular sulcus and drains the heart myocardium directly into the right atrium | ||||
| coronary sulcus | sulcus that marks the boundary between the atria and ventricles | ||||
| coronary veins | vessels that drain the heart and generally parallel the large surface arteries | ||||
| endocardium | innermost layer of the heart lining the heart chambers and heart valves; composed of endothelium reinforced with a thin layer of connective tissue that binds to the myocardium | ||||
| endothelium | layer of smooth, simple squamous epithelium that lines the endocardium and blood vessels | ||||
| epicardial coronary arteries | surface arteries of the heart that generally follow the sulci | ||||
| epicardium | innermost layer of the serous pericardium and the outermost layer of the heart wall | ||||
| foramen ovale | opening in the fetal heart that allows blood to flow directly from the right atrium to the left atrium, bypassing the fetal pulmonary circuit | ||||
| fossa ovalis | oval-shaped depression in the interatrial septum that marks the former location of the foramen ovale | ||||
| great cardiac vein | vessel that follows the interventricular sulcus on the anterior surface of the heart and flows along the coronary sulcus into the coronary sinus on the posterior surface; parallels the anterior interventricular artery and drains the areas supplied by this vessel | ||||
| hypertrophic cardiomyopathy | pathological enlargement of the heart, generally for no known reason | ||||
| inferior vena cava | large systemic vein that returns blood to the heart from the inferior portion of the body | ||||
| interatrial septum | cardiac septum located between the two atria; contains the fossa ovalis after birth | ||||
| interventricular septum | cardiac septum located between the two ventricles | ||||
| left atrioventricular valve | (also, mitral valve or bicuspid valve) valve located between the left atrium and ventricle; consists of two flaps of tissue | ||||
| marginal arteries | branches of the right coronary artery that supply blood to the superficial portions of the right ventricle | ||||
| mesothelium | simple squamous epithelial portion of serous membranes, such as the superficial portion of the epicardium (the visceral pericardium) and the deepest portion of the pericardium (the parietal pericardium) | ||||
| middle cardiac vein | vessel that parallels and drains the areas supplied by the posterior interventricular artery; drains into the great cardiac vein | ||||
| mitral valve | (also, left atrioventricular valve or bicuspid valve) valve located between the left atrium and ventricle; consists of two flaps of tissue | ||||
| moderator band | band of myocardium covered by endocardium that arises from the inferior portion of the interventricular septum in the right ventricle and crosses to the anterior papillary muscle; contains conductile fibers that carry electrical signals followed by contraction of the heart | ||||
| myocardium | thickest layer of the heart composed of cardiac muscle cells built upon a framework of primarily collagenous fibers and blood vessels that supply it and the nervous fibers that help to regulate it | ||||
| papillary muscle | extension of the myocardium in the ventricles to which the chordae tendineae attach | ||||
| pectinate muscles | muscular ridges seen on the anterior surface of the right atrium | ||||
| pericardial cavity | cavity surrounding the heart filled with a lubricating serous fluid that reduces friction as the heart contracts | ||||
| pericardial sac | (also, pericardium) membrane that separates the heart from other mediastinal structures; consists of two distinct, fused sublayers: the fibrous pericardium and the parietal pericardium | ||||
| pericardium | (also, pericardial sac) membrane that separates the heart from other mediastinal structures; consists of two distinct, fused sublayers: the fibrous pericardium and the parietal pericardium | ||||
| posterior cardiac vein | vessel that parallels and drains the areas supplied by the marginal artery branch of the circumflex artery; drains into the great cardiac vein | ||||
| posterior interventricular artery | (also, posterior descending artery) branch of the right coronary artery that runs along the posterior portion of the interventricular sulcus toward the apex of the heart and gives rise to branches that supply the interventricular septum and portions of both ventricles | ||||
| posterior interventricular sulcus | sulcus located between the left and right ventricles on the anterior surface of the heart | ||||
| pulmonary arteries | left and right branches of the pulmonary trunk that carry deoxygenated blood from the heart to each of the lungs | ||||
| pulmonary capillaries | capillaries surrounding the alveoli of the lungs where gas exchange occurs: carbon dioxide exits the blood and oxygen enters | ||||
| pulmonary circuit | blood flow to and from the lungs | ||||
| pulmonary trunk | large arterial vessel that carries blood ejected from the right ventricle; divides into the left and right pulmonary arteries | ||||
| pulmonary valve | (also, pulmonary semilunar valve, the pulmonic valve, or the right semilunar valve) valve at the base of the pulmonary trunk that prevents backflow of blood into the right ventricle; consists of three flaps | ||||
| pulmonary veins | veins that carry highly oxygenated blood into the left atrium, which pumps the blood into the left ventricle, which in turn pumps oxygenated blood into the aorta and to the many branches of the systemic circuit | ||||
| right atrioventricular valve | (also, tricuspid valve) valve located between the right atrium and ventricle; consists of three flaps of tissue | ||||
| semilunar valves | valves located at the base of the pulmonary trunk and at the base of the aorta | ||||
| septum | (plural = septa) walls or partitions that divide the heart into chambers | ||||
| septum primum | flap of tissue in the fetus that covers the foramen ovale within a few seconds after birth | ||||
| small cardiac vein | parallels the right coronary artery and drains blood from the posterior surfaces of the right atrium and ventricle; drains into the great cardiac vein | ||||
| sulcus | (plural = sulci) fat-filled groove visible on the surface of the heart; coronary vessels are also located in these areas | ||||
| superior vena cava | large systemic vein that returns blood to the heart from the superior portion of the body | ||||
| systemic circuit | blood flow to and from virtually all of the tissues of the body | ||||
| trabeculae carneae | ridges of muscle covered by endocardium located in the ventricles | ||||
| tricuspid valve | term used most often in clinical settings for the right atrioventricular valve | ||||
| valve | in the cardiovascular system, a specialized structure located within the heart or vessels that ensures one-way flow of blood | ||||
| ventricle | one of the primary pumping chambers of the heart located in the lower portion of the heart; the left ventricle is the major pumping chamber on the lower left side of the heart that ejects blood into the systemic circuit via the aorta and receives blood from the left atrium; the right ventricle is the major pumping chamber on the lower right side of the heart that ejects blood into the pulmonary circuit via the pulmonary trunk and receives blood from the right atrium | ||||
| artificial pacemaker | medical device that transmits electrical signals to the heart to ensure that it contracts and pumps blood to the body | ||||
| atrioventricular bundle | (also, bundle of His) group of specialized myocardial conductile cells that transmit the impulse from the AV node through the interventricular septum; form the left and right atrioventricular bundle branches | ||||
| atrioventricular bundle branches | (also, left or right bundle branches) specialized myocardial conductile cells that arise from the bifurcation of the atrioventricular bundle and pass through the interventricular septum; lead to the Purkinje fibers and also to the right papillary muscle via the moderator band | ||||
| atrioventricular (AV) node | clump of myocardial cells located in the inferior portion of the right atrium within the atrioventricular septum; receives the impulse from the SA node, pauses, and then transmits it into specialized conducting cells within the interventricular septum | ||||
| autorhythmicity | ability of cardiac muscle to initiate its own electrical impulse that triggers the mechanical contraction that pumps blood at a fixed pace without nervous or endocrine control | ||||
| Bachmann’s bundle | (also, interatrial band) group of specialized conducting cells that transmit the impulse directly from the SA node in the right atrium to the left atrium | ||||
| bundle of His | (also, atrioventricular bundle) group of specialized myocardial conductile cells that transmit the impulse from the AV node through the interventricular septum; form the left and right atrioventricular bundle branches | ||||
| electrocardiogram (ECG) | surface recording of the electrical activity of the heart that can be used for diagnosis of irregular heart function; also abbreviated as EKG | ||||
| heart block | interruption in the normal conduction pathway | ||||
| interatrial band | (also, Bachmann’s bundle) group of specialized conducting cells that transmit the impulse directly from the SA node in the right atrium to the left atrium | ||||
| intercalated disc | physical junction between adjacent cardiac muscle cells; consisting of desmosomes, specialized linking proteoglycans, and gap junctions that allow passage of ions between the two cells | ||||
| internodal pathways | specialized conductile cells within the atria that transmit the impulse from the SA node throughout the myocardial cells of the atrium and to the AV node | ||||
| myocardial conducting cells | specialized cells that transmit electrical impulses throughout the heart and trigger contraction by the myocardial contractile cells | ||||
| myocardial contractile cells | bulk of the cardiac muscle cells in the atria and ventricles that conduct impulses and contract to propel blood | ||||
| P wave | component of the electrocardiogram that represents the depolarization of the atria | ||||
| pacemaker | cluster of specialized myocardial cells known as the SA node that initiates the sinus rhythm | ||||
| Purkinje fibers | (also, subendocardial conducting network) specialized myocardial conducting fibers that arise from the bundle branches and spread the impulse to the myocardial contraction fibers of the ventricles | ||||
| QRS complex | component of the electrocardiogram that represents the depolarization of the ventricles and includes, as a component, the repolarization of the atria | ||||
| sinoatrial (SA) node | known as the pacemaker, a specialized clump of myocardial conducting cells located in the superior portion of the right atrium that has the highest inherent rate of depolarization that then spreads throughout the heart | ||||
| sinus rhythm | normal contractile pattern of the heart | ||||
| subendocardial conducting network | (also, Purkinje fibers) specialized myocardial conducting fibers that arise from the bundle branches and spread the impulse to the myocardial contraction fibers of the ventricles | ||||
| T wave | component of the electrocardiogram that represents the repolarization of the ventricles | ||||
| cardiac cycle | period of time between the onset of atrial contraction (atrial systole) and ventricular relaxation (ventricular diastole) | ||||
| diastole | period of time when the heart muscle is relaxed and the chambers fill with blood | ||||
| end diastolic volume (EDV) | (also, preload) the amount of blood in the ventricles at the end of atrial systole just prior to ventricular contraction | ||||
| end systolic volume (ESV) | amount of blood remaining in each ventricle following systole | ||||
| heart sounds | sounds heard via auscultation with a stethoscope of the closing of the atrioventricular valves (“lub”) and semilunar valves (“dub”) | ||||
| isovolumetric contraction | (also, isovolumic contraction) initial phase of ventricular contraction in which tension and pressure in the ventricle increase, but no blood is pumped or ejected from the heart | ||||
| isovolumetric ventricular relaxation phase | (also, isovolumic ventricular relaxation phase) initial phase of the ventricular diastole when pressure in the ventricles drops below pressure in the two major arteries, the pulmonary trunk, and the aorta, and blood attempts to flow back into the ventricles, closing the two semilunar valves | ||||
| murmur | unusual heart sound detected by auscultation; typically related to septal or valve defects | ||||
| preload | (also, end diastolic volume) amount of blood in the ventricles at the end of atrial systole just prior to ventricular contraction | ||||
| systole | period of time when the heart muscle is contracting | ||||
| ventricular ejection phase | second phase of ventricular systole during which blood is pumped from the ventricle | ||||
| bulbus cordis | portion of the primitive heart tube that will eventually develop into the right ventricle | ||||
| cardiogenic area | area near the head of the embryo where the heart begins to develop 18–19 days after fertilization | ||||
| cardiogenic cords | two strands of tissue that form within the cardiogenic area | ||||
| endocardial tubes | stage in which lumens form within the expanding cardiogenic cords, forming hollow structures | ||||
| heart bulge | prominent feature on the anterior surface of the heart, reflecting early cardiac development | ||||
| mesoderm | one of the three primary germ layers that differentiate early in embryonic development | ||||
| primitive atrium | portion of the primitive heart tube that eventually becomes the anterior portions of both the right and left atria, and the two auricles | ||||
| primitive heart tube | singular tubular structure that forms from the fusion of the two endocardial tubes | ||||
| primitive ventricle | portion of the primitive heart tube that eventually forms the left ventricle | ||||
| sinus venosus | develops into the posterior portion of the right atrium, the SA node, and the coronary sinus | ||||
| truncus arteriosus | portion of the primitive heart that will eventually divide and give rise to the ascending aorta and pulmonary trunk | ||||
| arteriole | (also, resistance vessel) very small artery that leads to a capillary | ||||
| arteriovenous anastomosis | short vessel connecting an arteriole directly to a venule and bypassing the capillary beds | ||||
| artery | blood vessel that conducts blood away from the heart; may be a conducting or distributing vessel | ||||
| capacitance | ability of a vein to distend and store blood | ||||
| capacitance vessels | veins | ||||
| capillary | smallest of blood vessels where physical exchange occurs between the blood and tissue cells surrounded by interstitial fluid | ||||
| capillary bed | network of 10–100 capillaries connecting arterioles to venules | ||||
| continuous capillary | most common type of capillary, found in virtually all tissues except epithelia and cartilage; contains very small gaps in the endothelial lining that permit exchange | ||||
| elastic artery | (also, conducting artery) artery with abundant elastic fibers located closer to the heart, which maintains the pressure gradient and conducts blood to smaller branches | ||||
| external elastic membrane | membrane composed of elastic fibers that separates the tunica media from the tunica externa; seen in larger arteries | ||||
| fenestrated capillary | type of capillary with pores or fenestrations in the endothelium that allow for rapid passage of certain small materials | ||||
| internal elastic membrane | membrane composed of elastic fibers that separates the tunica intima from the tunica media; seen in larger arteries | ||||
| lumen | interior of a tubular structure such as a blood vessel or a portion of the alimentary canal through which blood, chyme, or other substances travel | ||||
| metarteriole | short vessel arising from a terminal arteriole that branches to supply a capillary bed | ||||
| microcirculation | blood flow through the capillaries | ||||
| muscular artery | (also, distributing artery) artery with abundant smooth muscle in the tunica media that branches to distribute blood to the arteriole network | ||||
| nervi vasorum | small nerve fibers found in arteries and veins that trigger contraction of the smooth muscle in their walls | ||||
| perfusion | distribution of blood into the capillaries so the tissues can be supplied | ||||
| precapillary sphincters | circular rings of smooth muscle that surround the entrance to a capillary and regulate blood flow into that capillary | ||||
| sinusoid capillary | rarest type of capillary, which has extremely large intercellular gaps in the basement membrane in addition to clefts and fenestrations; found in areas such as the bone marrow and liver where passage of large molecules occurs | ||||
| thoroughfare channel | continuation of the metarteriole that enables blood to bypass a capillary bed and flow directly into a venule, creating a vascular shunt | ||||
| tunica externa | (also, tunica adventitia) outermost layer or tunic of a vessel (except capillaries) | ||||
| tunica intima | (also, tunica interna) innermost lining or tunic of a vessel | ||||
| tunica media | middle layer or tunic of a vessel (except capillaries) | ||||
| vasa vasorum | small blood vessels located within the walls or tunics of larger vessels that supply nourishment to and remove wastes from the cells of the vessels | ||||
| vascular shunt | continuation of the metarteriole and thoroughfare channel that allows blood to bypass the capillary beds to flow directly from the arterial to the venous circulation | ||||
| vasoconstriction | constriction of the smooth muscle of a blood vessel, resulting in a decreased vascular diameter | ||||
| vasodilation | relaxation of the smooth muscle in the wall of a blood vessel, resulting in an increased vascular diameter | ||||
| vasomotion | irregular, pulsating flow of blood through capillaries and related structures | ||||
| vein | blood vessel that conducts blood toward the heart | ||||
| venous reserve | volume of blood contained within systemic veins in the integument, bone marrow, and liver that can be returned to the heart for circulation, if needed | ||||
| venule | small vessel leading from the capillaries to veins | ||||
| blood flow | movement of blood through a vessel, tissue, or organ that is usually expressed in terms of volume per unit of time | ||||
| blood pressure | force exerted by the blood against the wall of a vessel or heart chamber; can be described with the more generic term hydrostatic pressure | ||||
| compliance | degree to which a blood vessel can stretch as opposed to being rigid | ||||
| diastolic pressure | lower number recorded when measuring arterial blood pressure; represents the minimal value corresponding to the pressure that remains during ventricular relaxation | ||||
| hypoxia | lack of oxygen supply to the tissues | ||||
| ischemia | insufficient blood flow to the tissues | ||||
| pulse | alternating expansion and recoil of an artery as blood moves through the vessel; an indicator of heart rate | ||||
| pulse pressure | difference between the systolic and diastolic pressures | ||||
| resistance | any condition or parameter that slows or counteracts the flow of blood | ||||
| respiratory pump | increase in the volume of the thorax during inhalation that decreases air pressure, enabling venous blood to flow into the thoracic region, then exhalation increases pressure, moving blood into the atria | ||||
| skeletal muscle pump | effect on increasing blood pressure within veins by compression of the vessel caused by the contraction of nearby skeletal muscle | ||||
| systolic pressure | larger number recorded when measuring arterial blood pressure; represents the maximum value following ventricular contraction | ||||
| vascular tone | contractile state of smooth muscle in a blood vessel | ||||
| abdominal aorta | portion of the aorta inferior to the aortic hiatus and superior to the common iliac arteries | ||||
| adrenal artery | branch of the abdominal aorta; supplies blood to the adrenal (suprarenal) glands | ||||
| adrenal vein | drains the adrenal or suprarenal glands that are immediately superior to the kidneys; the right adrenal vein enters the inferior vena cava directly and the left adrenal vein enters the left renal vein | ||||
| anterior cerebral artery | arises from the internal carotid artery; supplies the frontal lobe of the cerebrum | ||||
| anterior communicating artery | anastomosis of the right and left internal carotid arteries; supplies blood to the brain | ||||
| anterior tibial artery | branches from the popliteal artery; supplies blood to the anterior tibial region; becomes the dorsalis pedis artery | ||||
| anterior tibial vein | forms from the dorsal venous arch; drains the area near the tibialis anterior muscle and leads to the popliteal vein | ||||
| aorta | largest artery in the body, originating from the left ventricle and descending to the abdominal region where it bifurcates into the common iliac arteries at the level of the fourth lumbar vertebra; arteries originating from the aorta distribute blood to virtually all tissues of the body | ||||
| aortic arch | arc that connects the ascending aorta to the descending aorta; ends at the intervertebral disk between the fourth and fifth thoracic vertebrae | ||||
| aortic hiatus | opening in the diaphragm that allows passage of the thoracic aorta into the abdominal region where it becomes the abdominal aorta | ||||
| arterial circle | (also, circle of Willis) anastomosis located at the base of the brain that ensures continual blood supply; formed from branches of the internal carotid and vertebral arteries; supplies blood to the brain | ||||
| ascending aorta | initial portion of the aorta, rising from the left ventricle for a distance of approximately 5 cm | ||||
| axillary artery | continuation of the subclavian artery as it penetrates the body wall and enters the axillary region; supplies blood to the region near the head of the humerus (humeral circumflex arteries); the majority of the vessel continues into the brachium and becomes the brachial artery | ||||
| axillary vein | major vein in the axillary region; drains the upper limb and becomes the subclavian vein | ||||
| azygos vein | originates in the lumbar region and passes through the diaphragm into the thoracic cavity on the right side of the vertebral column; drains blood from the intercostal veins, esophageal veins, bronchial veins, and other veins draining the mediastinal region; leads to the superior vena cava | ||||
| basilar artery | formed from the fusion of the two vertebral arteries; sends branches to the cerebellum, brain stem, and the posterior cerebral arteries; the main blood supply to the brain stem | ||||
| basilic vein | superficial vein of the arm that arises from the palmar venous arches, intersects with the median cubital vein, parallels the ulnar vein, and continues into the upper arm; along with the brachial vein, it leads to the axillary vein | ||||
| brachial artery | continuation of the axillary artery in the brachium; supplies blood to much of the brachial region; gives off several smaller branches that provide blood to the posterior surface of the arm in the region of the elbow; bifurcates into the radial and ulnar arteries at the coronoid fossa | ||||
| brachial vein | deeper vein of the arm that forms from the radial and ulnar veins in the lower arm; leads to the axillary vein | ||||
| brachiocephalic artery | single vessel located on the right side of the body; the first vessel branching from the aortic arch; gives rise to the right subclavian artery and the right common carotid artery; supplies blood to the head, neck, upper limb, and wall of the thoracic region | ||||
| brachiocephalic vein | one of a pair of veins that form from a fusion of the external and internal jugular veins and the subclavian vein; subclavian, external and internal jugulars, vertebral, and internal thoracic veins lead to it; drains the upper thoracic region and flows into the superior vena cava | ||||
| bronchial artery | systemic branch from the aorta that provides oxygenated blood to the lungs in addition to the pulmonary circuit | ||||
| bronchial vein | drains the systemic circulation from the lungs and leads to the azygos vein | ||||
| cavernous sinus | enlarged vein that receives blood from most of the other cerebral veins and the eye socket, and leads to the petrosal sinus | ||||
| celiac trunk | (also, celiac artery) major branch of the abdominal aorta; gives rise to the left gastric artery, the splenic artery, and the common hepatic artery that forms the hepatic artery to the liver, the right gastric artery to the stomach, and the cystic artery to the gall bladder | ||||
| cephalic vein | superficial vessel in the upper arm; leads to the axillary vein | ||||
| cerebrovascular accident (CVA) | blockage of blood flow to the brain; also called a stroke | ||||
| circle of Willis | (also, arterial circle) anastomosis located at the base of the brain that ensures continual blood supply; formed from branches of the internal carotid and vertebral arteries; supplies blood to the brain | ||||
| common carotid artery | right common carotid artery arises from the brachiocephalic artery, and the left common carotid arises from the aortic arch; gives rise to the external and internal carotid arteries; supplies the respective sides of the head and neck | ||||
| common hepatic artery | branch of the celiac trunk that forms the hepatic artery, the right gastric artery, and the cystic artery | ||||
| common iliac artery | branch of the aorta that leads to the internal and external iliac arteries | ||||
| common iliac vein | one of a pair of veins that flows into the inferior vena cava at the level of L5; the left common iliac vein drains the sacral region; divides into external and internal iliac veins near the inferior portion of the sacroiliac joint | ||||
| cystic artery | branch of the common hepatic artery; supplies blood to the gall bladder | ||||
| deep femoral artery | branch of the femoral artery; gives rise to the lateral circumflex arteries | ||||
| deep femoral vein | drains blood from the deeper portions of the thigh and leads to the femoral vein | ||||
| descending aorta | portion of the aorta that continues downward past the end of the aortic arch; subdivided into the thoracic aorta and the abdominal aorta | ||||
| digital arteries | formed from the superficial and deep palmar arches; supply blood to the digits | ||||
| digital veins | drain the digits and feed into the palmar arches of the hand and dorsal venous arch of the foot | ||||
| dorsal arch | (also, arcuate arch) formed from the anastomosis of the dorsalis pedis artery and medial and plantar arteries; branches supply the distal portions of the foot and digits | ||||
| dorsal venous arch | drains blood from digital veins and vessels on the superior surface of the foot | ||||
| dorsalis pedis artery | forms from the anterior tibial artery; branches repeatedly to supply blood to the tarsal and dorsal regions of the foot | ||||
| esophageal artery | branch of the thoracic aorta; supplies blood to the esophagus | ||||
| esophageal vein | drains the inferior portions of the esophagus and leads to the azygos vein | ||||
| external carotid artery | arises from the common carotid artery; supplies blood to numerous structures within the face, lower jaw, neck, esophagus, and larynx | ||||
| external iliac artery | branch of the common iliac artery that leaves the body cavity and becomes a femoral artery; supplies blood to the lower limbs | ||||
| external iliac vein | formed when the femoral vein passes into the body cavity; drains the legs and leads to the common iliac vein | ||||
| external jugular vein | one of a pair of major veins located in the superficial neck region that drains blood from the more superficial portions of the head, scalp, and cranial regions, and leads to the subclavian vein | ||||
| femoral artery | continuation of the external iliac artery after it passes through the body cavity; divides into several smaller branches, the lateral deep femoral artery, and the genicular artery; becomes the popliteal artery as it passes posterior to the knee | ||||
| femoral circumflex vein | forms a loop around the femur just inferior to the trochanters; drains blood from the areas around the head and neck of the femur; leads to the femoral vein | ||||
| femoral vein | drains the upper leg; receives blood from the great saphenous vein, the deep femoral vein, and the femoral circumflex vein; becomes the external iliac vein when it crosses the body wall | ||||
| fibular vein | drains the muscles and integument near the fibula and leads to the popliteal vein | ||||
| genicular artery | branch of the femoral artery; supplies blood to the region of the knee | ||||
| gonadal artery | branch of the abdominal aorta; supplies blood to the gonads or reproductive organs; also described as ovarian arteries or testicular arteries, depending upon the sex of the individual | ||||
| gonadal vein | generic term for a vein draining a reproductive organ; may be either an ovarian vein or a testicular vein, depending on the sex of the individual | ||||
| great cerebral vein | receives most of the smaller vessels from the inferior cerebral veins and leads to the straight sinus | ||||
| great saphenous vein | prominent surface vessel located on the medial surface of the leg and thigh; drains the superficial portions of these areas and leads to the femoral vein | ||||
| hemiazygos vein | smaller vein complementary to the azygos vein; drains the esophageal veins from the esophagus and the left intercostal veins, and leads to the brachiocephalic vein via the superior intercostal vein | ||||
| hepatic artery proper | branch of the common hepatic artery; supplies systemic blood to the liver | ||||
| hepatic portal system | specialized circulatory pathway that carries blood from digestive organs to the liver for processing before being sent to the systemic circulation | ||||
| hepatic vein | drains systemic blood from the liver and flows into the inferior vena cava | ||||
| inferior mesenteric artery | branch of the abdominal aorta; supplies blood to the distal segment of the large intestine and rectum | ||||
| inferior phrenic artery | branch of the abdominal aorta; supplies blood to the inferior surface of the diaphragm | ||||
| inferior vena cava | large systemic vein that drains blood from areas largely inferior to the diaphragm; empties into the right atrium | ||||
| intercostal artery | branch of the thoracic aorta; supplies blood to the muscles of the thoracic cavity and vertebral column | ||||
| intercostal vein | drains the muscles of the thoracic wall and leads to the azygos vein | ||||
| internal carotid artery | arises from the common carotid artery and begins with the carotid sinus; goes through the carotid canal of the temporal bone to the base of the brain; combines with branches of the vertebral artery forming the arterial circle; supplies blood to the brain | ||||
| internal iliac artery | branch from the common iliac arteries; supplies blood to the urinary bladder, walls of the pelvis, external genitalia, and the medial portion of the femoral region; in females, also provide blood to the uterus and vagina | ||||
| internal iliac vein | drains the pelvic organs and integument; formed from several smaller veins in the region; leads to the common iliac vein | ||||
| internal jugular vein | one of a pair of major veins located in the neck region that passes through the jugular foramen and canal, flows parallel to the common carotid artery that is more or less its counterpart; primarily drains blood from the brain, receives the superficial facial vein, and empties into the subclavian vein | ||||
| internal thoracic artery | (also, mammary artery) arises from the subclavian artery; supplies blood to the thymus, pericardium of the heart, and the anterior chest wall | ||||
| internal thoracic vein | (also, internal mammary vein) drains the anterior surface of the chest wall and leads to the brachiocephalic vein | ||||
| lateral circumflex artery | branch of the deep femoral artery; supplies blood to the deep muscles of the thigh and the ventral and lateral regions of the integument | ||||
| lateral plantar artery | arises from the bifurcation of the posterior tibial arteries; supplies blood to the lateral plantar surfaces of the foot | ||||
| left gastric artery | branch of the celiac trunk; supplies blood to the stomach | ||||
| lumbar arteries | branches of the abdominal aorta; supply blood to the lumbar region, the abdominal wall, and spinal cord | ||||
| lumbar veins | drain the lumbar portion of the abdominal wall and spinal cord; the superior lumbar veins drain into the azygos vein on the right or the hemiazygos vein on the left; blood from these vessels is returned to the superior vena cava rather than the inferior vena cava | ||||
| maxillary vein | drains blood from the maxillary region and leads to the external jugular vein | ||||
| medial plantar artery | arises from the bifurcation of the posterior tibial arteries; supplies blood to the medial plantar surfaces of the foot | ||||
| median antebrachial vein | vein that parallels the ulnar vein but is more medial in location; intertwines with the palmar venous arches | ||||
| median cubital vein | superficial vessel located in the antecubital region that links the cephalic vein to the basilic vein in the form of a v; a frequent site for a blood draw | ||||
| median sacral artery | continuation of the aorta into the sacrum | ||||
| mediastinal artery | branch of the thoracic aorta; supplies blood to the mediastinum | ||||
| middle cerebral artery | another branch of the internal carotid artery; supplies blood to the temporal and parietal lobes of the cerebrum | ||||
| middle sacral vein | drains the sacral region and leads to the left common iliac vein | ||||
| occipital sinus | enlarged vein that drains the occipital region near the falx cerebelli and flows into the left and right transverse sinuses, and also into the vertebral veins | ||||
| ophthalmic artery | branch of the internal carotid artery; supplies blood to the eyes | ||||
| ovarian artery | branch of the abdominal aorta; supplies blood to the ovary, uterine (Fallopian) tube, and uterus | ||||
| ovarian vein | drains the ovary; the right ovarian vein leads to the inferior vena cava and the left ovarian vein leads to the left renal vein | ||||
| palmar arches | superficial and deep arches formed from anastomoses of the radial and ulnar arteries; supply blood to the hand and digital arteries | ||||
| palmar venous arches | drain the hand and digits, and feed into the radial and ulnar veins | ||||
| parietal branches | (also, somatic branches) group of arterial branches of the thoracic aorta; includes those that supply blood to the thoracic cavity, vertebral column, and the superior surface of the diaphragm | ||||
| pericardial artery | branch of the thoracic aorta; supplies blood to the pericardium | ||||
| petrosal sinus | enlarged vein that receives blood from the cavernous sinus and flows into the internal jugular vein | ||||
| phrenic vein | drains the diaphragm; the right phrenic vein flows into the inferior vena cava and the left phrenic vein leads to the left renal vein | ||||
| plantar arch | formed from the anastomosis of the dorsalis pedis artery and medial and plantar arteries; branches supply the distal portions of the foot and digits | ||||
| plantar veins | drain the foot and lead to the plantar venous arch | ||||
| plantar venous arch | formed from the plantar veins; leads to the anterior and posterior tibial veins through anastomoses | ||||
| popliteal artery | continuation of the femoral artery posterior to the knee; branches into the anterior and posterior tibial arteries | ||||
| popliteal vein | continuation of the femoral vein behind the knee; drains the region behind the knee and forms from the fusion of the fibular and anterior and posterior tibial veins | ||||
| posterior cerebral artery | branch of the basilar artery that forms a portion of the posterior segment of the arterial circle; supplies blood to the posterior portion of the cerebrum and brain stem | ||||
| posterior communicating artery | branch of the posterior cerebral artery that forms part of the posterior portion of the arterial circle; supplies blood to the brain | ||||
| posterior tibial artery | branch from the popliteal artery that gives rise to the fibular or peroneal artery; supplies blood to the posterior tibial region | ||||
| posterior tibial vein | forms from the dorsal venous arch; drains the area near the posterior surface of the tibia and leads to the popliteal vein | ||||
| pulmonary artery | one of two branches, left and right, that divides off from the pulmonary trunk and leads to smaller arterioles and eventually to the pulmonary capillaries | ||||
| pulmonary circuit | system of blood vessels that provide gas exchange via a network of arteries, veins, and capillaries that run from the heart, through the body, and back to the lungs | ||||
| pulmonary trunk | single large vessel exiting the right ventricle that divides to form the right and left pulmonary arteries | ||||
| pulmonary veins | two sets of paired vessels, one pair on each side, that are formed from the small venules leading away from the pulmonary capillaries that flow into the left atrium | ||||
| radial artery | formed at the bifurcation of the brachial artery; parallels the radius; gives off smaller branches until it reaches the carpal region where it fuses with the ulnar artery to form the superficial and deep palmar arches; supplies blood to the lower arm and carpal region | ||||
| radial vein | parallels the radius and radial artery; arises from the palmar venous arches and leads to the brachial vein | ||||
| renal artery | branch of the abdominal aorta; supplies each kidney | ||||
| renal vein | largest vein entering the inferior vena cava; drains the kidneys and leads to the inferior vena cava | ||||
| right gastric artery | branch of the common hepatic artery; supplies blood to the stomach | ||||
| sigmoid sinuses | enlarged veins that receive blood from the transverse sinuses; flow through the jugular foramen and into the internal jugular vein | ||||
| small saphenous vein | located on the lateral surface of the leg; drains blood from the superficial regions of the lower leg and foot, and leads to the popliteal vein | ||||
| splenic artery | branch of the celiac trunk; supplies blood to the spleen | ||||
| straight sinus | enlarged vein that drains blood from the brain; receives most of the blood from the great cerebral vein and flows into the left or right transverse sinus | ||||
| subclavian artery | right subclavian arises from the brachiocephalic artery, whereas the left subclavian artery arises from the aortic arch; gives rise to the internal thoracic, vertebral, and thyrocervical arteries; supplies blood to the arms, chest, shoulders, back, and central nervous system | ||||
| subclavian vein | located deep in the thoracic cavity; becomes the axillary vein as it enters the axillary region; drains the axillary and smaller local veins near the scapular region; leads to the brachiocephalic vein | ||||
| subscapular vein | drains blood from the subscapular region and leads to the axillary vein | ||||
| superior mesenteric artery | branch of the abdominal aorta; supplies blood to the small intestine (duodenum, jejunum, and ileum), the pancreas, and a majority of the large intestine | ||||
| superior phrenic artery | branch of the thoracic aorta; supplies blood to the superior surface of the diaphragm | ||||
| superior sagittal sinus | enlarged vein located midsagittally between the meningeal and periosteal layers of the dura mater within the falx cerebri; receives most of the blood drained from the superior surface of the cerebrum and leads to the inferior jugular vein and the vertebral vein | ||||
| superior vena cava | large systemic vein; drains blood from most areas superior to the diaphragm; empties into the right atrium | ||||
| temporal vein | drains blood from the temporal region and leads to the external jugular vein | ||||
| testicular artery | branch of the abdominal aorta; will ultimately travel outside the body cavity to the testes and form one component of the spermatic cord | ||||
| testicular vein | drains the testes and forms part of the spermatic cord; the right testicular vein empties directly into the inferior vena cava and the left testicular vein empties into the left renal vein | ||||
| thoracic aorta | portion of the descending aorta superior to the aortic hiatus | ||||
| thyrocervical artery | arises from the subclavian artery; supplies blood to the thyroid, the cervical region, the upper back, and shoulder | ||||
| transient ischemic attack (TIA) | temporary loss of neurological function caused by a brief interruption in blood flow; also known as a mini-stroke | ||||
| transverse sinuses | pair of enlarged veins near the lambdoid suture that drain the occipital, sagittal, and straight sinuses, and leads to the sigmoid sinuses | ||||
| trunk | large vessel that gives rise to smaller vessels | ||||
| ulnar artery | formed at the bifurcation of the brachial artery; parallels the ulna; gives off smaller branches until it reaches the carpal region where it fuses with the radial artery to form the superficial and deep palmar arches; supplies blood to the lower arm and carpal region | ||||
| ulnar vein | parallels the ulna and ulnar artery; arises from the palmar venous arches and leads to the brachial vein | ||||
| vertebral artery | arises from the subclavian artery and passes through the vertebral foramen through the foramen magnum to the brain; joins with the internal carotid artery to form the arterial circle; supplies blood to the brain and spinal cord | ||||
| vertebral vein | arises from the base of the brain and the cervical region of the spinal cord; passes through the intervertebral foramina in the cervical vertebrae; drains smaller veins from the cranium, spinal cord, and vertebrae, and leads to the brachiocephalic vein; counterpart of the vertebral artery | ||||
| visceral branches | branches of the descending aorta that supply blood to the viscera | ||||
| angioblasts | stem cells that give rise to blood vessels | ||||
| angiogenesis | development of new blood vessels from existing vessels | ||||
| blood islands | masses of developing blood vessels and formed elements from mesodermal cells scattered throughout the embryonic disc | ||||
| ductus arteriosus | shunt in the fetal pulmonary trunk that diverts oxygenated blood back to the aorta | ||||
| ductus venosus | shunt that causes oxygenated blood to bypass the fetal liver on its way to the inferior vena cava | ||||
| foramen ovale | shunt that directly connects the right and left atria and helps to divert oxygenated blood from the fetal pulmonary circuit | ||||
| hemangioblasts | embryonic stem cells that appear in the mesoderm and give rise to both angioblasts and pluripotent stem cells | ||||
| umbilical arteries | pair of vessels that runs within the umbilical cord and carries fetal blood low in oxygen and high in waste to the placenta for exchange with maternal blood | ||||
| umbilical vein | single vessel that originates in the placenta and runs within the umbilical cord, carrying oxygen- and nutrient-rich blood to the fetal heart | ||||
| vascular tubes | rudimentary blood vessels in a developing fetus | ||||
| 1st line of defense | temporal classification for the barrier defenses of the immune system that serve to prevent infection | ||||
| 2nd line of defense | temporal classification for the innate immune response that rapidly, but nonspecifically responds to pathogens to slow the spread of infection and also promotes healing after tissue damage | ||||
| 3rd line of defense | temporal classification for the adaptive immune response that responds more slowly, but also specifically and more effectively to eradicate infection | ||||
| adaptive immune response | relatively slow but very specific and effective immune response controlled by lymphocytes | ||||
| afferent lymphatic vessels | lead into a lymph node | ||||
| antibody | antigen-specific protein secreted by plasma cells; immunoglobulin | ||||
| antigen | molecule recognized by the receptors of B and T lymphocytes | ||||
| barrier defenses | antipathogen defenses deriving from a barrier that physically prevents pathogens from entering the body to establish an infection | ||||
| B cells | lymphocytes that act by differentiating into an antibody-secreting plasma cell | ||||
| bone marrow | tissue found inside bones; the site of all blood cell differentiation and maturation of B lymphocytes | ||||
| chyle | lipid-rich lymph inside the lymphatic capillaries of the small intestine | ||||
| cisterna chyli | bag-like vessel that forms the beginning of the thoracic duct | ||||
| efferent lymphatic vessels | lead out of a lymph node | ||||
| germinal centers | clusters of rapidly proliferating B cells found in secondary lymphoid tissues | ||||
| high endothelial venules | vessels containing unique endothelial cells specialized to allow migration of lymphocytes from the blood to the lymph node | ||||
| immune system | series of barriers, cells, and soluble mediators that combine to response to infections of the body with pathogenic organisms | ||||
| innate immune response | rapid but relatively nonspecific immune response | ||||
| lymph | fluid contained within the lymphatic system | ||||
| lymph node | one of the bean-shaped organs found associated with the lymphatic vessels | ||||
| lymphatic capillaries | smallest of the lymphatic vessels and the origin of lymph flow | ||||
| lymphatic system | network of lymphatic vessels, lymph nodes, and ducts that carries lymph from the tissues and back to the bloodstream. | ||||
| lymphatic trunks | large lymphatics that collect lymph from smaller lymphatic vessels and empties into the blood via lymphatic ducts | ||||
| lymphocytes | white blood cells characterized by a large nucleus and small rim of cytoplasm | ||||
| lymphoid nodules | unencapsulated patches of lymphoid tissue found throughout the body | ||||
| mucosa-associated lymphoid tissue (MALT) | lymphoid nodule associated with the mucosa | ||||
| naïve lymphocyte | mature B or T cell that has not yet encountered antigen for the first time | ||||
| natural killer cell (NK) | cytotoxic lymphocyte of innate immune response | ||||
| plasma cell | differentiated B cell that is actively secreting antibody | ||||
| primary lymphoid organ | site where lymphocytes mature and proliferate; red bone marrow and thymus gland | ||||
| right lymphatic duct | drains lymph fluid from the upper right side of body into the right subclavian vein | ||||
| secondary lymphoid organs | sites where lymphocytes mount adaptive immune responses; examples include lymph nodes and spleen | ||||
| spleen | secondary lymphoid organ that filters pathogens from the blood (white pulp) and removes degenerating or damaged blood cells (red pulp) | ||||
| T cell | lymphocyte that acts by secreting molecules that regulate the immune system or by causing the destruction of foreign cells, viruses, and cancer cells | ||||
| thoracic duct | large duct that drains lymph from the lower limbs, left thorax, left upper limb, and the left side of the head | ||||
| thymocyte | immature T cell found in the thymus | ||||
| thymus | primary lymphoid organ; where T lymphocytes proliferate and mature | ||||
| tonsils | lymphoid nodules associated with the nasopharynx | ||||
| acute inflammation | inflammation occurring for a limited time period; rapidly developing | ||||
| antigen-presenting cell (APC) | cell that presents a fragment of an antigen to T cells to induce an adaptive immune response | ||||
| chemokine | soluble, long-range, cell-to-cell communication molecule | ||||
| chronic inflammation | inflammation occurring for long periods of time | ||||
| complement | enzymatic cascade of constitutive blood proteins that have antipathogen effects, including the direct killing of bacteria | ||||
| cytokine | soluble, short-range, cell-to-cell communication molecule | ||||
| dendritic cell | phagocyte and antigen-presenting cell (APC) typically found in epithelial tissues such as the epidermis | ||||
| early induced immune response | includes antimicrobial proteins stimulated during the first several days of an infection | ||||
| histamine | vasoactive mediator in granules of mast cells and is the primary cause of allergies and anaphylactic shock | ||||
| inflammation | basic innate immune response characterized by heat, redness, pain, and swelling | ||||
| interferons | early induced proteins made in virally infected cells that cause nearby cells to make antiviral proteins | ||||
| macrophage | ameoboid phagocyte found in several tissues throughout the body; also an APC | ||||
| mast cell | cell found in the skin and the lining of body cells that contains cytoplasmic granules with vasoactive mediators such as histamine | ||||
| monocyte | precursor to macrophages and dendritic cells seen in the blood | ||||
| neutrophil | phagocytic white blood cell recruited from the bloodstream to the site of infection via the bloodstream | ||||
| phagocytosis | movement of material from the outside to the inside of the cells via vesicles made from invaginations of the plasma membrane | ||||
| active immunity | immunity developed from an individual’s own immune system | ||||
| central tolerance | B cell tolerance induced in immature B cells of the bone marrow | ||||
| clonal anergy | process whereby B cells that react to soluble antigens in bone marrow are made nonfunctional | ||||
| clonal deletion | removal of self-reactive B cells by inducing apoptosis | ||||
| immunoglobulin | protein antibody; occurs as one of five main classes | ||||
| passive immunity | transfer of immunity to a pathogen to an individual that lacks immunity to this pathogen usually by the injection of antibodies | ||||
| peripheral tolerance | mature B cell made tolerant by lack of T cell help | ||||
| T cell-dependent antigen | antigen that binds to B cells, which requires signals from T cells to make antibody | ||||
| T cell-independent antigen | binds to B cells, which do not require signals from T cells to make antibody | ||||
| antigen presentation | binding of processed antigen to the protein-binding cleft of a major histocompatibility complex molecule | ||||
| clone | group of lymphocytes sharing the same antigen receptor | ||||
| clonal expansion | growth of a clone of selected lymphocytes | ||||
| clonal selection | stimulating growth of lymphocytes that have specific receptors | ||||
| constant region domain | part of a lymphocyte antigen receptor that does not vary much between different receptor types | ||||
| cytotoxic T cells (Tc, T8, or CD8+ T cells) | T lymphocytes with the ability to induce apoptosis in target cells | ||||
| effector T cells | immune cells with a direct, adverse effect on a pathogen | ||||
| helper T cells (Th, T4, or CD4+ T cells) | T cells that secrete cytokines to enhance other immune responses, involved in activation of both B and T cell lymphocytes | ||||
| immunological memory | ability of the adaptive immune response to mount a stronger and faster immune response upon re-exposure to a pathogen | ||||
| memory T cells | long-lived immune cell reserved for future exposure to an pathogen | ||||
| primary adaptive response | immune system’s response to the first exposure to a pathogen | ||||
| regulatory T cells (Treg) | (also, suppressor T cells) class of CD4 T cells that regulates other T cell responses | ||||
| secondary adaptive response | immune response observed upon re-exposure to a pathogen, which is stronger and faster than a primary response | ||||
| neutralization | inactivation of a virus by the binding of specific antibody | ||||
| seroconversion | clearance of pathogen in the serum and the simultaneous rise of serum antibody | ||||
| severe combined immunodeficiency disease (SCID) | genetic mutation that affects both T cell and B cell arms of the immune response | ||||
| ala | (plural = alae) small, flaring structure of a nostril that forms the lateral side of the external nares | ||||
| alar cartilage | cartilage that supports the apex of the nose and helps shape the nares; it is connected to the septal cartilage and connective tissue of the alae | ||||
| alveolar duct | small tube that leads from the terminal bronchiole to the respiratory bronchiole and is the point of attachment for alveoli | ||||
| alveolar macrophage | immune system cell of the alveolus that removes debris and pathogens | ||||
| alveolar pore | opening that allows airflow between neighboring alveoli | ||||
| alveolar sac | cluster of alveoli | ||||
| alveolus | small, grape-like sac that performs gas exchange in the lungs | ||||
| apex | tip of the external nose | ||||
| bronchial tree | collective name for the multiple branches of the bronchi and bronchioles of the respiratory system | ||||
| bridge | portion of the external nose that lies in the area of the nasal bones | ||||
| bronchiole | branch of bronchi that are 1 mm or less in diameter and terminate at alveolar sacs | ||||
| bronchus | tube connected to the trachea that branches into many subsidiaries and provides a passageway for air to enter and leave the lungs | ||||
| conducting zone | region of the respiratory system that includes the organs and structures that provide passageways for air and are not directly involved in gas exchange | ||||
| cricoid cartilage | portion of the larynx composed of a ring of cartilage with a wide posterior region and a thinner anterior region; attached to the esophagus | ||||
| dorsum nasi | intermediate portion of the external nose that connects the bridge to the apex and is supported by the nasal bone | ||||
| epiglottis | leaf-shaped piece of elastic cartilage that is a portion of the larynx that swings to close the trachea during swallowing | ||||
| external nose | region of the nose that is easily visible to others | ||||
| fauces | portion of the posterior oral cavity that connects the oral cavity to the oropharynx | ||||
| fibroelastic membrane | specialized membrane that connects the ends of the C-shape cartilage in the trachea; contains smooth muscle fibers | ||||
| glottis | opening between the vocal folds through which air passes when producing speech | ||||
| laryngeal prominence | region where the two lamina of the thyroid cartilage join, forming a protrusion known as “Adam’s apple” | ||||
| laryngopharynx | portion of the pharynx bordered by the oropharynx superiorly and esophagus and trachea inferiorly; serves as a route for both air and food | ||||
| larynx | cartilaginous structure that produces the voice, prevents food and beverages from entering the trachea, and regulates the volume of air that enters and leaves the lungs | ||||
| lingual tonsil | lymphoid tissue located at the base of the tongue | ||||
| meatus | one of three recesses (superior, middle, and inferior) in the nasal cavity attached to the conchae that increase the surface area of the nasal cavity | ||||
| naris | (plural = nares) opening of the nostrils | ||||
| nasal bone | bone of the skull that lies under the root and bridge of the nose and is connected to the frontal and maxillary bones | ||||
| nasal septum | wall composed of bone and cartilage that separates the left and right nasal cavities | ||||
| nasopharynx | portion of the pharynx flanked by the conchae and oropharynx that serves as an airway | ||||
| oropharynx | portion of the pharynx flanked by the nasopharynx, oral cavity, and laryngopharynx that is a passageway for both air and food | ||||
| palatine tonsil | one of the paired structures composed of lymphoid tissue located anterior to the uvula at the roof of isthmus of the fauces | ||||
| paranasal sinus | one of the cavities within the skull that is connected to the conchae that serve to warm and humidify incoming air, produce mucus, and lighten the weight of the skull; consists of frontal, maxillary, sphenoidal, and ethmoidal sinuses | ||||
| pharyngeal tonsil | structure composed of lymphoid tissue located in the nasopharynx | ||||
| pharynx | region of the conducting zone that forms a tube of skeletal muscle lined with respiratory epithelium; located between the nasal conchae and the esophagus and trachea | ||||
| philtrum | concave surface of the face that connects the apex of the nose to the top lip | ||||
| pulmonary surfactant | substance composed of phospholipids and proteins that reduces the surface tension of the alveoli; made by type II alveolar cells | ||||
| respiratory bronchiole | specific type of bronchiole that leads to alveolar sacs | ||||
| respiratory epithelium | ciliated lining of much of the conducting zone that is specialized to remove debris and pathogens, and produce mucus | ||||
| respiratory membrane | alveolar and capillary wall together, which form an air-blood barrier that facilitates the simple diffusion of gases | ||||
| respiratory zone | includes structures of the respiratory system that are directly involved in gas exchange | ||||
| root | region of the external nose between the eyebrows | ||||
| thyroid cartilage | largest piece of cartilage that makes up the larynx and consists of two lamina | ||||
| trachea | tube composed of cartilaginous rings and supporting tissue that connects the lung bronchi and the larynx; provides a route for air to enter and exit the lung | ||||
| trachealis muscle | smooth muscle located in the fibroelastic membrane of the trachea | ||||
| true vocal cord | one of the pair of folded, white membranes that have a free inner edge that oscillates as air passes through to produce sound | ||||
| type I alveolar cell | squamous epithelial cells that are the major cell type in the alveolar wall; highly permeable to gases | ||||
| type II alveolar cell | cuboidal epithelial cells that are the minor cell type in the alveolar wall; secrete pulmonary surfactant | ||||
| vestibular fold | part of the folded region of the glottis composed of mucous membrane; supports the epiglottis during swallowing | ||||
| bronchoconstriction | decrease in the size of the bronchiole due to contraction of the muscular wall | ||||
| bronchodilation | increase in the size of the bronchiole due to contraction of the muscular wall | ||||
| cardiac notch | indentation on the surface of the left lung that allows space for the heart | ||||
| hilum | concave structure on the mediastinal surface of the lungs where blood vessels, lymphatic vessels, nerves, and a bronchus enter the lung | ||||
| lung | organ of the respiratory system that performs gas exchange | ||||
| parietal pleura | outermost layer of the pleura that connects to the thoracic wall, mediastinum, and diaphragm | ||||
| pleural cavity | space between the visceral and parietal pleurae | ||||
| pleural fluid | substance that acts as a lubricant for the visceral and parietal layers of the pleura during the movement of breathing | ||||
| pulmonary artery | artery that arises from the pulmonary trunk and carries deoxygenated, arterial blood to the alveoli | ||||
| pulmonary plexus | network of autonomic nervous system fibers found near the hilum of the lung | ||||
| visceral pleura | innermost layer of the pleura that is superficial to the lungs and extends into the lung fissures | ||||
| bronchial bud | structure in the developing embryo that forms when the laryngotracheal bud extends and branches to form two bulbous structures | ||||
| foregut | endoderm of the embryo towards the head region | ||||
| laryngotracheal | bud forms from the lung bud, has a tracheal end and bulbous bronchial buds at the distal end | ||||
| lung bud | median dome that forms from the endoderm of the foregut | ||||
| olfactory pit | invaginated ectodermal tissue in the anterior portion of the head region of an embryo that will form the nasal cavity | ||||
| accessory digestive organ | includes teeth, tongue, salivary glands, gallbladder, liver, and pancreas | ||||
| alimentary canal | continuous muscular digestive tube that extends from the mouth to the anus | ||||
| motility | movement of food through the GI tract | ||||
| mucosa | innermost lining of the alimentary canal | ||||
| muscularis | muscle (skeletal or smooth) layer of the alimentary canal wall | ||||
| myenteric plexus | (plexus of Auerbach) major nerve supply to alimentary canal wall; controls motility | ||||
| retroperitoneal | located posterior to the peritoneum | ||||
| serosa | outermost layer of the alimentary canal wall present in regions within the abdominal cavity | ||||
| submucosa | layer of dense connective tissue in the alimentary canal wall that binds the overlying mucosa to the underlying muscularis | ||||
| submucosal plexus | (plexus of Meissner) nerve supply that regulates activity of glands and smooth muscle | ||||
| absorption | passage of digested products from the intestinal lumen through mucosal cells and into the bloodstream or lacteals | ||||
| chemical digestion | enzymatic breakdown of food | ||||
| chyme | soupy liquid created when food is mixed with digestive juices | ||||
| defecation | elimination of undigested substances from the body in the form of feces | ||||
| ingestion | taking food into the GI tract through the mouth | ||||
| mastication | chewing | ||||
| mechanical digestion | chewing, mixing, and segmentation that prepares food for chemical digestion | ||||
| peristalsis | muscular contractions and relaxations that propel food through the GI tract | ||||
| propulsion | voluntary process of swallowing and the involuntary process of peristalsis that moves food through the digestive tract | ||||
| segmentation | alternating contractions and relaxations of non-adjacent segments of the intestine that move food forward and backward, breaking it apart and mixing it with digestive juices | ||||
| bolus | mass of chewed food | ||||
| cementum | bone-like tissue covering the root of a tooth | ||||
| crown | portion of tooth visible superior to the gum line | ||||
| cuspid | (also, canine) pointed tooth used for tearing and shredding food | ||||
| deciduous tooth | one of 20 “baby teeth” | ||||
| deglutition | three-stage process of swallowing | ||||
| dens | tooth | ||||
| dentin | bone-like tissue immediately deep to the enamel of the crown or cementum of the root of a tooth | ||||
| dentition | set of teeth | ||||
| enamel | covering of the dentin of the crown of a tooth | ||||
| esophagus | muscular tube that runs from the pharynx to the stomach | ||||
| fauces | opening between the oral cavity and the oropharynx | ||||
| gingiva | gum | ||||
| incisor | midline, chisel-shaped tooth used for cutting into food | ||||
| labium | lip | ||||
| labial frenulum | midline mucous membrane fold that attaches the inner surface of the lips to the gums | ||||
| laryngopharynx | part of the pharynx that functions in respiration and digestion | ||||
| lingual frenulum | mucous membrane fold that attaches the bottom of the tongue to the floor of the mouth | ||||
| lingual lipase | digestive enzyme from glands in the tongue that acts on triglycerides | ||||
| lower esophageal sphincter | smooth muscle sphincter that regulates food movement from the esophagus to the stomach | ||||
| molar | tooth used for crushing and grinding food | ||||
| oral cavity | (also, buccal cavity) mouth | ||||
| oral vestibule | part of the mouth bounded externally by the cheeks and lips, and internally by the gums and teeth | ||||
| oropharynx | part of the pharynx continuous with the oral cavity that functions in respiration and digestion | ||||
| palatoglossal arch | muscular fold that extends from the lateral side of the soft palate to the base of the tongue | ||||
| palatopharyngeal arch | muscular fold that extends from the lateral side of the soft palate to the side of the pharynx | ||||
| parotid gland | one of a pair of major salivary glands located inferior and anterior to the ears | ||||
| permanent tooth | one of 32 adult teeth | ||||
| pharynx | throat | ||||
| premolar | (also, bicuspid) transitional tooth used for mastication, crushing, and grinding food | ||||
| pulp cavity | deepest portion of a tooth, containing nerve endings and blood vessels | ||||
| root | portion of a tooth embedded in the alveolar processes beneath the gum line | ||||
| saliva | aqueous solution of proteins and ions secreted into the mouth by the salivary glands | ||||
| salivary amylase | digestive enzyme in saliva that acts on starch | ||||
| salivary gland | an exocrine gland that secretes a digestive fluid called saliva | ||||
| salivation | secretion of saliva | ||||
| soft palate | posterior region of the bottom portion of the nasal cavity that consists of skeletal muscle | ||||
| sublingual gland | one of a pair of major salivary glands located beneath the tongue | ||||
| submandibular gland | one of a pair of major salivary glands located in the floor of the mouth | ||||
| tongue | accessory digestive organ of the mouth, the bulk of which is composed of skeletal muscle | ||||
| upper esophageal sphincter | skeletal muscle sphincter that regulates food movement from the pharynx to the esophagus | ||||
| voluntary phase | initial phase of deglutition, in which the bolus moves from the mouth to the oropharynx | ||||
| body | mid-portion of the stomach | ||||
| cardia | (also, cardiac region) part of the stomach surrounding the cardiac orifice (esophageal hiatus) | ||||
| cephalic phase | (also, reflex phase) initial phase of gastric secretion that occurs before food enters the stomach | ||||
| chief cell | gastric gland cell that secretes pepsinogen | ||||
| enteroendocrine cell | gastric gland cell that releases hormones | ||||
| fundus | dome-shaped region of the stomach above and to the left of the cardia | ||||
| G cell | gastrin-secreting enteroendocrine cell | ||||
| gastric emptying | process by which mixing waves gradually cause the release of chyme into the duodenum | ||||
| gastric gland | gland in the stomach mucosal epithelium that produces gastric juice | ||||
| gastric phase | phase of gastric secretion that begins when food enters the stomach | ||||
| gastric pit | narrow channel formed by the epithelial lining of the stomach mucosa | ||||
| gastrin | peptide hormone that stimulates secretion of hydrochloric acid and gut motility | ||||
| hydrochloric acid (HCl) | digestive acid secreted by parietal cells in the stomach | ||||
| intrinsic factor | glycoprotein required for vitamin B12 absorption in the small intestine | ||||
| intestinal phase | phase of gastric secretion that begins when chyme enters the intestine | ||||
| mixing wave | unique type of peristalsis that occurs in the stomach | ||||
| mucosal barrier | protective barrier that prevents gastric juice from destroying the stomach itself | ||||
| mucous neck cell | gastric gland cell that secretes a uniquely acidic mucus | ||||
| parietal cell | gastric gland cell that secretes hydrochloric acid and intrinsic factor | ||||
| pepsinogen | inactive form of pepsin | ||||
| pyloric antrum | wider, more superior part of the pylorus | ||||
| pyloric canal | narrow, more inferior part of the pylorus | ||||
| pyloric sphincter | sphincter that controls stomach emptying | ||||
| pylorus | lower, funnel-shaped part of the stomach that is continuous with the duodenum | ||||
| ruga | fold of alimentary canal mucosa and submucosa in the empty stomach and other organs | ||||
| stomach | alimentary canal organ that contributes to chemical and mechanical digestion of food from the esophagus before releasing it, as chyme, to the small intestine | ||||
| anal canal | final segment of the large intestine | ||||
| anal column | long fold of mucosa in the anal canal | ||||
| anal sinus | recess between anal columns | ||||
| appendix | (vermiform appendix) coiled tube attached to the cecum | ||||
| ascending colon | first region of the colon | ||||
| bacterial flora | bacteria in the large intestine | ||||
| brush border | fuzzy appearance of the small intestinal mucosa created by microvilli | ||||
| cecum | pouch forming the beginning of the large intestine | ||||
| circular fold | (also, plica circulare) deep fold in the mucosa and submucosa of the small intestine | ||||
| colon | part of the large intestine between the cecum and the rectum | ||||
| descending colon | part of the colon between the transverse colon and the sigmoid colon | ||||
| duodenal gland | (also, Brunner’s gland) mucous-secreting gland in the duodenal submucosa | ||||
| duodenum | first part of the small intestine, which starts at the pyloric sphincter and ends at the jejunum | ||||
| epiploic appendage | small sac of fat-filled visceral peritoneum attached to teniae coli | ||||
| external anal sphincter | voluntary skeletal muscle sphincter in the anal canal | ||||
| feces | semisolid waste product of digestion | ||||
| flatus | gas in the intestine | ||||
| gastrocolic reflex | propulsive movement in the colon activated by the presence of food in the stomach | ||||
| gastroileal reflex | long reflex that increases the strength of segmentation in the ileum | ||||
| haustrum | small pouch in the colon created by tonic contractions of teniae coli | ||||
| haustral contraction | slow segmentation in the large intestine | ||||
| hepatopancreatic ampulla | (also, ampulla of Vater) bulb-like point in the wall of the duodenum where the bile duct and main pancreatic duct unite | ||||
| hepatopancreatic sphincter | (also, sphincter of Oddi) sphincter regulating the flow of bile and pancreatic juice into the duodenum | ||||
| ileocecal sphincter | sphincter located where the small intestine joins with the large intestine | ||||
| ileum | end of the small intestine between the jejunum and the large intestine | ||||
| internal anal sphincter | involuntary smooth muscle sphincter in the anal canal | ||||
| intestinal gland | (also, crypt of Lieberkühn) gland in the small intestinal mucosa that secretes intestinal juice | ||||
| intestinal juice | mixture of water and mucus that helps absorb nutrients from chyme | ||||
| jejunum | middle part of the small intestine between the duodenum and the ileum | ||||
| lacteal | lymphatic capillary in the villi | ||||
| large intestine | terminal portion of the alimentary canal | ||||
| left colic flexure | (also, splenic flexure) point where the transverse colon curves below the inferior end of the spleen | ||||
| main pancreatic duct | (also, duct of Wirsung) duct through which pancreatic juice drains from the pancreas | ||||
| major duodenal papilla | point at which the hepatopancreatic ampulla opens into the duodenum | ||||
| mass movement | long, slow, peristaltic wave in the large intestine | ||||
| mesoappendix | mesentery of the appendix | ||||
| microvillus | small projection of the plasma membrane of the absorptive cells of the small intestinal mucosa | ||||
| migrating motility complex | form of peristalsis in the small intestine | ||||
| motilin | hormone that initiates migrating motility complexes | ||||
| pectinate line | horizontal line that runs like a ring, perpendicular to the inferior margins of the anal sinuses | ||||
| rectal valve | one of three transverse folds in the rectum where feces is separated from flatus | ||||
| rectum | part of the large intestine between the sigmoid colon and anal canal | ||||
| right colic flexure | (also, hepatic flexure) point, at the inferior surface of the liver, where the ascending colon turns abruptly to the left | ||||
| saccharolytic fermentation | anaerobic decomposition of carbohydrates | ||||
| sigmoid colon | end portion of the colon, which terminates at the rectum | ||||
| small intestine | section of the alimentary canal where most digestion and absorption occurs | ||||
| tenia coli | one of three smooth muscle bands that make up the longitudinal muscle layer of the muscularis in all of the large intestine except the terminal end | ||||
| transverse colon | part of the colon between the ascending colon and the descending colon | ||||
| Valsalva’s maneuver | voluntary contraction of the diaphragm and abdominal wall muscles and closing of the glottis, which increases intra-abdominal pressure and facilitates defecation | ||||
| villus | projection of the mucosa of the small intestine | ||||
| accessory duct | (also, duct of Santorini) duct that runs from the pancreas into the duodenum | ||||
| acinus | cluster of glandular epithelial cells in the pancreas that secretes pancreatic juice in the pancreas | ||||
| bile | alkaline solution produced by the liver and important for the emulsification of lipids | ||||
| bile canaliculus | small duct between hepatocytes that collects bile | ||||
| bilirubin | main bile pigment, which is responsible for the brown color of feces | ||||
| central vein | vein that receives blood from hepatic sinusoids | ||||
| common bile duct | structure formed by the union of the common hepatic duct and the gallbladder’s cystic duct | ||||
| common hepatic duct | duct formed by the merger of the two hepatic ducts | ||||
| cystic duct | duct through which bile drains and enters the gallbladder | ||||
| enterohepatic circulation | recycling mechanism that conserves bile salts | ||||
| enteropeptidase | intestinal brush-border enzyme that activates trypsinogen to trypsin | ||||
| gallbladder | accessory digestive organ that stores and concentrates bile | ||||
| hepatic artery | artery that supplies oxygenated blood to the liver | ||||
| hepatic lobule | hexagonal-shaped structure composed of hepatocytes that radiate outward from a central vein | ||||
| hepatic portal vein | vein that supplies deoxygenated nutrient-rich blood to the liver | ||||
| hepatic sinusoid | blood capillaries between rows of hepatocytes that receive blood from the hepatic portal vein and the branches of the hepatic artery | ||||
| hepatic vein | vein that drains into the inferior vena cava | ||||
| hepatocytes | major functional cells of the liver | ||||
| liver | largest gland in the body whose main digestive function is the production of bile | ||||
| pancreas | accessory digestive organ that secretes pancreatic juice | ||||
| pancreatic juice | secretion of the pancreas containing digestive enzymes and bicarbonate | ||||
| porta hepatis | “gateway to the liver” where the hepatic artery and hepatic portal vein enter the liver | ||||
| portal triad | bile duct, hepatic artery branch, and hepatic portal vein branch | ||||
| reticuloendothelial cell | (also, Kupffer cell) phagocyte in hepatic sinusoids that filters out material from venous blood from the alimentary canal | ||||
| Bowman’s capsule | cup-shaped sack lined by a simple squamous epithelium (parietal surface) and specialized cells called podocytes (visceral surface) that participate in the filtration process; receives the filtrate which then passes on to the PCTs | ||||
| calyces | cup-like structures receiving urine from the collecting ducts where it passes on to the renal pelvis and ureter | ||||
| cortical nephrons | nephrons with loops of Henle that do not extend into the renal medulla | ||||
| distal convoluted tubules | portions of the nephron distal to the loop of Henle that receive hyposmotic filtrate from the loop of Henle and empty into collecting ducts | ||||
| efferent arteriole | arteriole carrying blood from the glomerulus to the capillary beds around the convoluted tubules and loop of Henle; portion of the portal system | ||||
| glomerulus | tuft of capillaries surrounded by Bowman’s capsule; filters the blood based on size | ||||
| juxtamedullary nephrons | nephrons adjacent to the border of the cortex and medulla with loops of Henle that extend into the renal medulla | ||||
| loop of Henle | descending and ascending portions between the proximal and distal convoluted tubules; those of cortical nephrons do not extend into the medulla, whereas those of juxtamedullary nephrons do extend into the medulla | ||||
| nephrons | functional units of the kidney that carry out all filtration and modification to produce urine; consist of renal corpuscles, proximal and distal convoluted tubules, and descending and ascending loops of Henle; drain into collecting ducts | ||||
| medulla | inner region of kidney containing the renal pyramids | ||||
| peritubular capillaries | second capillary bed of the renal portal system; surround the proximal and distal convoluted tubules; associated with the vasa recta | ||||
| proximal convoluted tubules (PCTs) | tortuous tubules receiving filtrate from Bowman’s capsule; most active part of the nephron in reabsorption and secretion | ||||
| renal columns | extensions of the renal cortex into the renal medulla; separates the renal pyramids; contains blood vessels and connective tissues | ||||
| renal corpuscle | consists of the glomerulus and Bowman’s capsule | ||||
| renal cortex | outer part of kidney containing all of the nephrons; some nephrons have loops of Henle extending into the medulla | ||||
| renal fat pad | adipose tissue between the renal fascia and the renal capsule that provides protective cushioning to the kidney | ||||
| renal hilum | recessed medial area of the kidney through which the renal artery, renal vein, ureters, lymphatics, and nerves pass | ||||
| renal papillae | medullary area of the renal pyramids where collecting ducts empty urine into the minor calyces | ||||
| renal pyramids | six to eight cone-shaped tissues in the medulla of the kidney containing collecting ducts and the loops of Henle of juxtamedullary nephrons | ||||
| vasa recta | branches of the efferent arterioles that parallel the course of the loops of Henle and are continuous with the peritubular capillaries; with the glomerulus, form a portal system | ||||
| angiotensin-converting enzyme (ACE) | enzyme produced by the lungs that catalyzes the reaction of inactive angiotensin I into active angiotensin II | ||||
| angiotensin I | protein produced by the enzymatic action of renin on angiotensinogen; inactive precursor of angiotensin II | ||||
| angiotensin II | protein produced by the enzymatic action of ACE on inactive angiotensin I; actively causes vasoconstriction and stimulates aldosterone release by the adrenal cortex | ||||
| angiotensinogen | inactive protein in the circulation produced by the liver; precursor of angiotensin I; must be modified by the enzymes renin and ACE to be activated | ||||
| aquaporin | protein-forming water channels through the lipid bilayer of the cell; allows water to cross; activation in the collecting ducts is under the control of ADH | ||||
| brush border | formed by microvilli on the surface of certain cuboidal cells; in the kidney it is found in the PCT; increases surface area for absorption in the kidney | ||||
| fenestrations | small windows through a cell, allowing rapid filtration based on size; formed in such a way as to allow substances to cross through a cell without mixing with cell contents | ||||
| filtration slits | formed by pedicels of podocytes; substances filter between the pedicels based on size | ||||
| forming urine | filtrate undergoing modifications through secretion and reabsorption before true urine is produced | ||||
| juxtaglomerular apparatus (JGA) | located at the juncture of the DCT and the afferent and efferent arterioles of the glomerulus; plays a role in the regulation of renal blood flow and GFR | ||||
| juxtaglomerular cell | modified smooth muscle cells of the afferent arteriole; secretes renin in response to a drop in blood pressure | ||||
| macula densa | cells found in the part of the DCT forming the JGA; sense Na+ concentration in the forming urine | ||||
| mesangial | contractile cells found in the glomerulus; can contract or relax to regulate filtration rate | ||||
| pedicels | finger-like projections of podocytes surrounding glomerular capillaries; interdigitate to form a filtration membrane | ||||
| podocytes | cells forming finger-like processes; form the visceral layer of Bowman’s capsule; pedicels of the podocytes interdigitate to form a filtration membrane | ||||
| renin | enzyme produced by juxtaglomerular cells in response to decreased blood pressure or sympathetic nervous activity; catalyzes the conversion of angiotensinogen into angiotensin I | ||||
| anatomical sphincter | smooth or skeletal muscle surrounding the lumen of a vessel or hollow organ that can restrict flow when contracted | ||||
| detrusor muscle | smooth muscle in the bladder wall; fibers run in all directions to reduce the size of the organ when emptying it of urine | ||||
| external urinary sphincter | skeletal muscle; must be relaxed consciously to void urine | ||||
| internal urinary sphincter | smooth muscle at the juncture of the bladder and urethra; relaxes as the bladder fills to allow urine into the urethra | ||||
| incontinence | loss of ability to control micturition | ||||
| micturition | also called urination or voiding | ||||
| physiological sphincter | sphincter consisting of circular smooth muscle indistinguishable from adjacent muscle but possessing differential innervations, permitting its function as a sphincter; structurally weak | ||||
| retroperitoneal | outside the peritoneal cavity; in the case of the kidney and ureters, between the parietal peritoneum and the abdominal wall | ||||
| sacral micturition center | group of neurons in the sacral region of the spinal cord that controls urination; acts reflexively unless its action is modified by higher brain centers to allow voluntary urination | ||||
| trigone | area at the base of the bladder marked by the two ureters in the posterior–lateral aspect and the urethral orifice in the anterior aspect oriented like points on a triangle | ||||
| urethra | transports urine from the bladder to the outside environment | ||||
| anuria | absence of urine produced; production of 50 mL or less per day | ||||
| leukocyte esterase | enzyme produced by leukocytes that can be detected in the urine and that serves as an indirect indicator of urinary tract infection | ||||
| oliguria | below normal urine production of 400–500 mL/day | ||||
| polyuria | urine production in excess of 2.5 L/day; may be caused by diabetes insipidus, diabetes mellitus, or excessive use of diuretics | ||||
| specific gravity | weight of a liquid compared to pure water, which has a specific gravity of 1.0; any solute added to water will increase its specific gravity | ||||
| urinalysis | analysis of urine to diagnose disease | ||||
| urochrome | heme-derived pigment that imparts the typical yellow color of urine | ||||
| blood–testis barrier | tight junctions between Sertoli cells that prevent bloodborne pathogens from gaining access to later stages of spermatogenesis and prevent the potential for an autoimmune reaction to haploid sperm | ||||
| bulbourethral glands | (also, Cowper’s glands) glands that secrete a lubricating mucus that cleans and lubricates the urethra prior to and during ejaculation | ||||
| corpus cavernosum | either of two columns of erectile tissue in the penis that fill with blood during an erection | ||||
| corpus spongiosum | (plural = corpora cavernosa) column of erectile tissue in the penis that fills with blood during an erection and surrounds the penile urethra on the ventral portion of the penis | ||||
| ductus deferens | (also, vas deferens) duct that transports sperm from the epididymis through the spermatic cord and into the ejaculatory duct; also referred as the vas deferens | ||||
| ejaculatory duct | duct that connects the ampulla of the ductus deferens with the duct of the seminal vesicle at the prostatic urethra | ||||
| epididymis | (plural = epididymides) coiled tubular structure in which sperm start to mature and are stored until ejaculation | ||||
| gamete | haploid reproductive cell that contributes genetic material to form an offspring | ||||
| glans penis | bulbous end of the penis that contains a large number of nerve endings | ||||
| gonadotropin-releasing hormone (GnRH) | hormone released by the hypothalamus that regulates the production of follicle-stimulating hormone and luteinizing hormone from the pituitary gland | ||||
| gonads | reproductive organs (testes in men and ovaries in women) that produce gametes and reproductive hormones | ||||
| inguinal canal | opening in abdominal wall that connects the testes to the abdominal cavity | ||||
| Leydig cells | cells between the seminiferous tubules of the testes that produce testosterone; a type of interstitial cell | ||||
| penis | male organ of copulation | ||||
| prepuce | (also, foreskin) flap of skin that forms a collar around, and thus protects and lubricates, the glans penis; also referred as the foreskin | ||||
| prostate gland | doughnut-shaped gland at the base of the bladder surrounding the urethra and contributing fluid to semen during ejaculation | ||||
| scrotum | external pouch of skin and muscle that houses the testes | ||||
| semen | ejaculatory fluid composed of sperm and secretions from the seminal vesicles, prostate, and bulbourethral glands | ||||
| seminal vesicle | gland that produces seminal fluid, which contributes to semen | ||||
| seminiferous tubules | tube structures within the testes where spermatogenesis occurs | ||||
| Sertoli cells | cells that support germ cells through the process of spermatogenesis; a type of sustentacular cell | ||||
| sperm | (also, spermatozoon) male gamete | ||||
| spermatic cord | bundle of nerves and blood vessels that supplies the testes; contains ductus deferens | ||||
| spermatid | immature sperm cells produced by meiosis II of secondary spermatocytes | ||||
| spermatocyte | cell that results from the division of spermatogonium and undergoes meiosis I and meiosis II to form spermatids | ||||
| spermatogenesis | formation of new sperm, occurs in the seminiferous tubules of the testes | ||||
| spermatogonia | (singular = spermatogonium) diploid precursor cells that become sperm | ||||
| spermiogenesis | transformation of spermatids to spermatozoa during spermatogenesis | ||||
| testes | (singular = testis) male gonads | ||||
| alveoli | (of the breast) milk-secreting cells in the mammary gland | ||||
| ampulla | (of the uterine tube) middle portion of the uterine tube in which fertilization often occurs | ||||
| antrum | fluid-filled chamber that characterizes a mature tertiary (antral) follicle | ||||
| areola | highly pigmented, circular area surrounding the raised nipple and containing areolar glands that secrete fluid important for lubrication during suckling | ||||
| Bartholin’s glands | (also, greater vestibular glands) glands that produce a thick mucus that maintains moisture in the vulva area; also referred to as the greater vestibular glands | ||||
| body of uterus | middle section of the uterus | ||||
| broad ligament | wide ligament that supports the uterus by attaching laterally to both sides of the uterus and pelvic wall | ||||
| cervix | elongate inferior end of the uterus where it connects to the vagina | ||||
| clitoris | (also, glans clitoris) nerve-rich area of the vulva that contributes to sexual sensation during intercourse | ||||
| corpus albicans | nonfunctional structure remaining in the ovarian stroma following structural and functional regression of the corpus luteum | ||||
| corpus luteum | transformed follicle after ovulation that secretes progesterone | ||||
| endometrium | inner lining of the uterus, part of which builds up during the secretory phase of the menstrual cycle and then sheds with menses | ||||
| fimbriae | fingerlike projections on the distal uterine tubes | ||||
| follicle | ovarian structure of one oocyte and surrounding granulosa (and later theca) cells | ||||
| folliculogenesis | development of ovarian follicles from primordial to tertiary under the stimulation of gonadotropins | ||||
| fundus | (of the uterus) domed portion of the uterus that is superior to the uterine tubes | ||||
| granulosa cells | supportive cells in the ovarian follicle that produce estrogen | ||||
| hymen | membrane that covers part of the opening of the vagina | ||||
| infundibulum | (of the uterine tube) wide, distal portion of the uterine tube terminating in fimbriae | ||||
| isthmus | narrow, medial portion of the uterine tube that joins the uterus | ||||
| labia majora | hair-covered folds of skin located behind the mons pubis | ||||
| labia minora | thin, pigmented, hairless flaps of skin located medial and deep to the labia majora | ||||
| lactiferous ducts | ducts that connect the mammary glands to the nipple and allow for the transport of milk | ||||
| lactiferous sinus | area of milk collection between alveoli and lactiferous duct | ||||
| mammary glands | glands inside the breast that secrete milk | ||||
| menarche | first menstruation in a pubertal female | ||||
| menses | shedding of the inner portion of the endometrium out though the vagina; also referred to as menstruation | ||||
| menses phase | phase of the menstrual cycle in which the endometrial lining is shed | ||||
| menstrual cycle | approximately 28-day cycle of changes in the uterus consisting of a menses phase, a proliferative phase, and a secretory phase | ||||
| mons pubis | mound of fatty tissue located at the front of the vulva | ||||
| myometrium | smooth muscle layer of uterus that allows for uterine contractions during labor and expulsion of menstrual blood | ||||
| oocyte | cell that results from the division of the oogonium and undergoes meiosis I at the LH surge and meiosis II at fertilization to become a haploid ovum | ||||
| oogenesis | process by which oogonia divide by mitosis to primary oocytes, which undergo meiosis to produce the secondary oocyte and, upon fertilization, the ovum | ||||
| oogonia | ovarian stem cells that undergo mitosis during female fetal development to form primary oocytes | ||||
| ovarian cycle | approximately 28-day cycle of changes in the ovary consisting of a follicular phase and a luteal phase | ||||
| ovaries | female gonads that produce oocytes and sex steroid hormones (notably estrogen and progesterone) | ||||
| ovulation | release of a secondary oocyte and associated granulosa cells from an ovary | ||||
| ovum | haploid female gamete resulting from completion of meiosis II at fertilization | ||||
| perimetrium | outer epithelial layer of uterine wall | ||||
| polar body | smaller cell produced during the process of meiosis in oogenesis | ||||
| primary follicles | ovarian follicles with a primary oocyte and one layer of cuboidal granulosa cells | ||||
| primordial follicles | least developed ovarian follicles that consist of a single oocyte and a single layer of flat (squamous) granulosa cells | ||||
| proliferative phase | phase of the menstrual cycle in which the endometrium proliferates | ||||
| rugae | (of the vagina) folds of skin in the vagina that allow it to stretch during intercourse and childbirth | ||||
| secondary follicles | ovarian follicles with a primary oocyte and multiple layers of granulosa cells | ||||
| secretory phase | phase of the menstrual cycle in which the endometrium secretes a nutrient-rich fluid in preparation for implantation of an embryo | ||||
| suspensory ligaments | bands of connective tissue that suspend the breast onto the chest wall by attachment to the overlying dermis | ||||
| tertiary follicles | (also, antral follicles) ovarian follicles with a primary or secondary oocyte, multiple layers of granulosa cells, and a fully formed antrum | ||||
| theca cells | estrogen-producing cells in a maturing ovarian follicle | ||||
| uterine tubes | (also, fallopian tubes or oviducts) ducts that facilitate transport of an ovulated oocyte to the uterus | ||||
| uterus | muscular hollow organ in which a fertilized egg develops into a fetus | ||||
| vagina | tunnel-like organ that provides access to the uterus for the insertion of semen and from the uterus for the birth of a baby | ||||
| vulva | external female genitalia | ||||
| Müllerian duct | duct system present in the embryo that will eventually form the internal female reproductive structures | ||||
| puberty | life stage during which a male or female adolescent becomes anatomically and physiologically capable of reproduction | ||||
| secondary sex characteristics | physical characteristics that are influenced by sex steroid hormones and have supporting roles in reproductive function | ||||
| Wolffian duct | duct system present in the embryo that will eventually form the internal male reproductive structures |