Glossary
- Page ID
- 38413
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| Words (or words that have the same definition) | The definition is case sensitive | (Optional) Image to display with the definition [Not displayed in Glossary, only in pop-up on pages] | (Optional) Caption for Image | (Optional) External or Internal Link | (Optional) Source for Definition |
|---|---|---|---|---|---|
| (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 |