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Medicine LibreTexts

Glossary

  • Page ID
    34308
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    Glossary Entries
    Word(s) Definition Image Caption Link Source
    Abdomen The part of the body below the diaphragm        
    Abomasum The final compartment of the stomach of ruminants. This the ‘true’ stomach where muscular walls churn the food and gastric juice is secreted        
    Absorption Passage of digested food from the gut into the blood        
    Accessory gland A gland that produces secretions that make up the liquid portion of semen        
    Acetylcholine A neurotransmitter released at a synapse        
    Acoustic Relating to sound        
    Active transport The movement of substances across a membrane against the concentration gradient. Requires energy        
    Adipose tissue Connective tissue in which the cells are filled with fat or lipid        
    Adrenal cortex Outer portion of adrenal gland        
    Adrenal medulla Inner portion of adrenal gland        
    Albumin The most common of the proteins in the plasma        
    Aldosterone The hormone produced by the adrenal cortex        
    Alimentary Concerning nutrition        
    Alimentary canal The long canal from the mouth to the anus through which food passes as it is digested and absorbed        
    Alkaline Containing few hydrogen ions. pH above 7        
    Alveolus An air sac in the lung, where gas exchange takes place        
    Amino acids Molecules containing nitrogen that are the building blocks of proteins        
    Amphibian Vertebrate Class containing the frogs and toads        
    Amylases Enzymes that split carbohydrates like starch and glycogen into monosaccharides like glucose        
    Anaemia A condition involving a low number of red blood cells or haemoglobin in blood        
    Antagonistic muscles A pair of muscles that work together such that as one contracts the other relaxes and vice versa.        
    Anterior Nearer to the front of the body (usually used in human anatomy)        
    Anterior pituitary gland Anterior portion of pituitary gland        
    Antibodies Proteins made in response to a stimulating molecule called an antigen. The basis for the immune response        
    Anticoagulant A substance that prevents blood clotting        
    Antidiuretic A substance that inhibits urine production        
    Antidiuretic hormone A hormone produced by posterior pituitary gland that stimulates water reabsorption from the kidney tubule        
    Antigens A substance that stimulates the body to produce an antibody        
    Anus The opening at the lower end of the rectum through which solid waste is eliminated.        
    Aorta The main artery to body and head from heart        
    Apex The pointed end of a cone shaped structure e.g. heart        
    Appendage A structure attached to the body        
    Appendage A structure attached to the body        
    Aqueous humor The watery fluid that fills the anterior chamber of the eye        
    Aqueous humor The watery fluid that fills the anterior chamber of the eye        
    Arteriole A small, almost microscopic, artery        
    Arteriole A small, almost microscopic, artery        
    Artery A blood vessel that carries blood away from the heart        
    Artery A blood vessel that carries blood away from the heart        
    Articulate To move against each other - as of bones        
    Articulation The point of contact between bones. Where they move against each other        
    Articulation The point of contact between bones. Where they move against each other.        
    Atlas First cervical vertebra        
    Atom A unit of matter that comprises a chemical element        
    Atrioventricular valve A valve that prevents blood flow backwards from ventricle to atrium        
    Atrium (pl. atria) One of two cranial chambers of heart        
    Auditory ossicle One of 3 small bones in middle ear        
    Autonomic nervous system The part of the vertebrate nervous system that innervates smooth and cardiac muscle and

    glandular tissues and governs involuntary actions. Consists of the sympathetic nervous

    system and the parasympathetic nervous system.

           
    Axillary lymph node A lymph node under junction of forelimb forelimb and body        
    Axis The second cervical vertebra        
    Axon A long extension from the neuron that carries nerve impulses away from the cell body        
    Ball and socket joint A synovial joint where rounded end of one bone fits into cup-shaped depression of another        
    Barb The part of the feather that sticks out of the shaft        
    Barbules The parts of a feather that grow out of the barbs. They have hooks and rolled edges to lock the barbs together        
    Basement membrane The thin membrane between epidermis and dermis        
    Basophil A white blood cell with granules in the cytoplasm        
    Biceps The muscle that extends from the shoulder to the elbow responsible for flexing the forearm        
    Bilateral Including both sides        
    Bile An alkaline secretion from liver that helps break down fats into small droplets        
    Binocular vision The placement of the eyes such that both see the same wide area but from slightly different angles        
    Binomial The two-part Latinized name of a species, consisting of genus consisting of genus and species names        
    Blastocyst A hollow ball of cells that develop from the fertilized ovum        
    Blind spot The area of retina at end of optic nerve where there are no receptor cells        
    Blood The fluid that circulates in the blood vessels        
    Blood pressure The pressure of blood on the walls of the blood vessels        
    Body cavity A space within the body that contains various organs        
    Bowman’s capsule The double walled globe at proximal end of nephron. Encloses glomerulus        
    Brain stem The part of the brain just above the spinal cord. Contains the medulla oblongata        
    Breed A race or variety        
    Bronchiole A branch of the bronchi in the respiratory system        
    Bronchus One of the large branches of the trachea        
    Buccal To do with the mouth        
    Callus A thickening of the skin or growth of new bone tissue in and around a fracture        
    Canines The long, cone-shaped teeth just behind the incisors        
    Carbohydrate An organic compound containing carbon, hydrogen and oxygen. Made up of sugar subunits        
    Cardiac cycle A complete heartbeat consisting of systole and diastole        
    Cardiac muscle The muscle that makes up the wall of the heart. Striated branched fibres        
    Cardiovascular system The body system comprising the heart, blood vessels and blood        
    Carnassial teeth The modified premolars and molars in carnivores that slice against each other like scissors for shearing flesh and bone.        
    Carotid artery The artery from aorta that supplies the head and brain        
    Carpal A bone of the “wrist”        
    Cartilage Dense connective tissue found at ends of long bones, in trachea, ear pinna. Also forms the skeleton of the foetus        
    Cataract A condition in which the lens becomes cloudy resulting in blurred vision.        
    Caudal Nearer to the tail than        
    Caudal vena cava The large vein that collects blood from the body caudal to the heart        
    Cell The basic structural and functional unit of all organisms        
    Cell division The process by which a cell reproduces itself. Two types: mitosis and meiosis        
    Cell inclusion A substance produced by cell that is free in cytoplasm i.e. not enclosed by a membrane        
    Cellular respiration The chemical pathway that produces energy in the cell

    It consumes a fuel, generally glucose, in the presence of oxygen

           
    Central nervous system The part of the nervous system consisting of the brain and spinal cord        
    Cephalic To do with the head        
    Cerebellum The part of the vertebrate hindbrain located dorsally; functions in unconscious coordination of movement and balance        
    Cerebral cortex The surface of the cerebrum; the largest and most complex part of the mammalian brain, containing sensory and motor nerve cell bodies of the cerebrum        
    Cerebrospinal fluid The fluid that circulates around and within brain brain and spinal cord        
    Cerebrum The dorsal portion of the brain composed of right and left hemispheres;

    the integrating center for memory, learning, emotions

           
    Cervical vertebrae The neck vertebrae        
    Cervix The neck of the uterus        
    Chemoreceptor A receptor that detects chemicals        
    Chorionic gonadotrophin The hormone secreted by the placenta that prevents uterine contractions before labour

    and prepares the mammary glands for lactation

           
    Choroid The middle coat of the eyeball        
    Chromosome One of the small dark staining bodies in the cell nucleus. Contains the DNA        
    Chyle The milky fluid found in the lacteals of the small intestine        
    Chyme The semi fluid mixture of partly digested food and digestive secretions in the stomach and small intestine        
    Cilium (pl. cilia) A hair like process projecting from a cell. Used to move cell substances along the surface of the cell        
    Class The taxonomic grouping of related, similar orders; category above order and below phylum        
    Clavicle The collar bone        
    Clot The process that changes liquid blood to a gelatinous mass        
    Coagulation The process by which blood clots        
    Coccygeal vertebrae The vertebrae of the tail        
    Coccyx The tail bones        
    Cochlea The coiled tube forming the portion of the inner ear that converts sound waves to nerve impulses        
    Collagen A protein that is the main organic constituent of connective tissue        
    Colon Part of the large intestine.        
    Colostrum The first milk, it contains antibodies.        
    Common bile duct The duct that carries both bile and pancreatic juice into the small intestine        
    Compact bone Dense bone made up of Haversian systems        
    Conditioned Reflex The response that is elicited by a stimulus after training has taken place        
    Condyle A rounded protuberance at the ends of some bones where it forms an articulation with another bone        
    Cone A light sensitive receptor in the retina that responds to colour        
    Congenital Present at the time of birth        
    Conjunctiva The delicate membrane covering the cornea of the eye        
    Connective tissue One of the 4 basic tissue types of the body. Binds and supports. Consists of cells and fibres in a matrixs        
    Constipation Decreased defecation due to decreased mobility of the intestines        
    Continuous breeding When breeding continues throughout the year        
    Cornea The transparent anterior layer of the eye through which the iris can be seen        
    Coronary artery The artery that supplies the heart muscle        
    Corpus luteum A yellow endocrine gland formed in the empty ovarian follicle after ovulation        
    Cortex The outer layer of an organ        
    Costal To do with a rib        
    Cowper’s gland One of the accessory glands of the male reproductive system        
    Cranial Towards the head        
    Cranial nerve One of the 12 nerves that leave the brain        
    Cranium The brain case in surrounds and protects young        
    Crop The bag-like structure at semi fluid portion of the base loss of the oesophagus in birds.In many birds it stores food before it enters the stomachA        
    Crop-milk Secretion produced by glands in the wall of the crop of in pigeons different doves Parents regurgitate it to feed their young        
    Cross section Crosswise slice of an animal or organ        
    Cross section Crosswise slice of an animal or organ        
    Cryptorchidism Undescended testes        
    Cryptorchidism Undescended testes        
    Cutaneous To do with the brain        
    Cutaneous To do with the skin        
    Cytology The study of cells        
    Cytosol The semi fluid portion of the cytoplasm        
    Dehydration Excessive loss of water from the body or its parts        
    Denaturation Disruption of the structure of a protein by heat, acids etc. to make it inactive        
    Dendrite Blood pressure in the arteries between the passage of the pulses        
    Dental formula The formula that describes the numbers of dogs        
    Dentine The tissue below the enamel in teeth        
    Dermis The layer of dense connective tissue lying under the epidermis        
    Diabetes insipidus The condition caused by under secretion of antidiuretic hormone (ADH). Symptom: excretion large amounts dilute urine        
    Diabetes mellitus The condition caused by under secretion of insulin. Symptoms: raised blood glucose levels, glucose in urine        
    Diaphragm The dome shaped skeletal muscle separating the thoracic from the abdominal cavities        
    Diaphysis        
    Diarrhoea Frequent defecation of liquid faeces        
    Diastema The space in the jaw in animals that have no (or reduced) canines        
    Diastole The phase of the heartbeat involving the relaxation of the ventricles        
    Diastolic blood pressure Blood pressure in the arteries between the passage of the pulses        
    Diffusion A nerve cell process movement carries the nerve impulses towards the cell body        
    Diffusion A passive process in the presence of movement of molecules from a region of high concentration to one of low concentration      
    Digestion The mechanical and physical breakdown layer of food        
    Digitigrade locomotion Locomotion on the “fingers” as in cats and dogs        
    Dilate To expand or swell        
    Dilate To expand or swell        
    Diploid Having a double set of chromosomes one maternal, one paternal        
    Diploid Having a double set of chromosomes one maternal, one paternal        
    Directional terms Terms that describe the different kinds of teeth        
    Directional terms Terms the body        
    Disaccharides Double sugar, consisting of two joined monosaccharides        
    Distal Farther away from the trunk of substances through the body or point of origin        
    Diuretic Fluid outside body cells        
    Dorsal Nearer the back compounds consisting of the animal than        
    Duodenum First part of the small intestine        
    Echolocation The use of high frequency sound like sonar and radar by animals (i.e. whales and bats) to locate objects in joint between the surrounding environment        
    Effector A muscle or gland that responds to a motor neuron impulse        
    Egestion The elimination insoluble protein formed from fibrinogen        
    Electrolyte A compound that separates into charged particles or ions        
    Electron microscope A microscope that focuses an electron beam through a specimen, resulting in resolving power two thousandfold greater than that anticoagulant used for biochemical tests for glucose        
    Element Any substance that cannot be broken down to any other substance        
    Embryo The shaft of any long bone        
    Embryo The young of any organism in an early stage of development        
    Emulsification The breakdown of large fat particles to smaller ones in the presence of bile        
    Enamel The hard white substance covering the crown of teeth        
    Endocrine gland A ductless gland that secretes hormones into the blood        
    Endometrium The inner lining of the uterus        
    Endoplasmic reticulum The network of membranous channels running through the cytoplasm of cells        
    Endothelium The layer of squamous epithelium that lines blood vessels        
    Enzyme The enlarged large intestine and caecum occupied by cellulose digesting micro-organisms        
    Eosinophil A white blood cell with granules in the cytoplasm        
    Eosinophil A white blood cell with granules in the cytoplasm        
    Epidermis The thin outer layer of the skin        
    Epididymis The organ composed of convoluted tubules that lies on the border of the testis Where sperm mature        
    Epiglottis The cartilage on the top of the larynx that closes the windpipe during swallowing        
    Epiphyseal line        
    Epiphyseal plate The cartilaginous plate at the end of a long bone where bone growth occurs        
    Epiphysis The end of a long bone        
    Epithelial tissue Tissue that forms outer part of skin, lines blood vessels, hollow organs and passages in the body        
    Erythrocyte A red blood cell        
    Erythrocyte A red blood cell        
    Essential amino acids The 10 amino acids that describe the locations of structures in relation to other structures or locations in the body        
    Essential amino acids The 10 amino acids that can not be made by animals and must be acquired in the diet        
    Eustachian tube The passage connecting middle ear to pharynx. Equalises air pressure in middle and outer ear        
    Evolution All the changes that have transformed life on Earth from its earliest beginnings to the diversity that characterizes it today        
    Excretion To cast out material from the body, cell or tissue        
    Exocrine gland A gland that secretes substances into a duct        
    Exocytosis The discharge of substances through the plasma membrane        
    Expiration Breathing out        
    Extension Bending of a joint so that the angle between the bones increases        
    Extracellular fluid Fluid outside body cells        
    Facilitated diffusion Diffusion across a membrane using a carrier substance        
    Facilitated diffusion Diffusion across a membrane using a carrier substance        
    Fallopian tube A chemical that reduces Antidiuretic hormone production and increases urine volume        
    Fallopian tube A slender tube through which eggs pass from an ovary to the uterus        
    Fats Biological compounds consisting of three fatty acids linked to one glycerol molecule        
    Feedback system The sequence of events where information about the status number of a situation is continually fed back to the central control region        
    Femur The long bone between the pelvis plane the knee        
    Fertilisation Penetration of ovum by sperm and union of nuclei        
    Fetlock The joint between the metacarpals or metatarsals and the phalanges in horse        
    Fibrin The insoluble protein formed from fibrinogen        
    Fibrinogen The protein in blood plasma essential for blood clotting        
    Fibrinogen The protein in blood plasma essential for blood clotting        
    Fibula The lateral bone of indigestible waste products from the body        
    Fibula The lateral bone of the lower hind limb        
    Filtrate The fluid produced by filtration of blood in the nephron        
    Flagellum A long hair like process e.g. tail of sperm        
    Flexion The movement involving decreasing the angle between two bones        
    Fluoroxylate An anticoagulant used for biochemical tests for glucose        
    Foetus Later stage of a light microscope        
    Foetus Later stage of development of a young animal        
    Follicle The cavity surrounding the developing ovum        
    Follicle stimulating

    hormone (FSH)

    Hormone secreted by anterior pituitary gland. Stimulates development of ovarian follicle        
    Foramen The muscles between the ribs.        
    Foramen magnum The hole at the base of the skull for passage of the spinal cord        
    Fossa A furrow or shallow depression in a bone        
    Fovea The area of the retina of greatest concentration of cone cells. Area of sharpest vision        
    Functional caecum The enlarged large intestine and caecum occupied by cellulose digesting micro-organisms        
    Gall bladder The small pouch that stores bile        
    Gall bladder        
    Gamete A substance that increases the speed of nerve chemical reaction        
    Gamete A reproductive cell - sperm or ovum        
    Ganglion A group of nerve cells outside central nervous system        
    Gas exchange The process in which oxygen from inhaled air is transferred into the blood and carbon dioxide from the blood is transferred into the alveoli        
    Gastric juice The digestive secretion produced by glands in the wall of the stomach        
    Gene The biological unit of heredity        
    Gestation The period of foetal development inside the uterus        
    Girdle An encircling or arching arrangement of bones        
    Gizzard The second part of the stomach slice of birds. In seed eating birds it contains pebbles and its muscular walls help grind the food        
    Gland Loin region of the back        
    Gliding joint The remnant of epiphyseal plate at end of long bone        
    Gliding joint A synovial joint with flat articulating surfaces that permits limited movements e.g. between carpals and tarsals        
    Glomerular capsule See Bowman’s capsule        
    Glomerulus Tuft of capillaries surrounded by the Bowman’s capsule in nephron        
    Glottis Vocal cords        
    Glucose The smallest sugar. Major energy source for all cells        
    Glycerol A molecule that combines with three fatty acid molecules to form a fat or oil        
    Glycogen A highly branched polymer of glucose. Energy store in body        
    Goitre The condition involving enlargement of thyroid gland        
    Golgi complex apparatus A cell organelle concerned with packaging, processing and secretion of organic molecules        
    Gonads The ovary and testes        
    Graafian follicle The mature ovarian follicle        
    Grey matter Area of the nervous system consisting of cell bodies        
    Growth hormone A hormone secreted by the anterior pituitary gland. Stimulates growth, particularly of the skeleton        
    Haematocrit The percentage of blood made up of red blood cells. Also called packed cell volume (PCV)        
    Haematuria Urine that contains red blood cells        
    Haemoglobin Pigment containing iron in red blood cells that allows them to carry oxygen        
    Haemolysis The escape five bones of haemoglobin from a red blood cell        
    Haemorrhage Bleeding        
    Haploid Having half the normal number of chromosomes, produced by meiosis        
    Haversian canal The canal down centre of a Haversian system        
    Haversian system The columns of boney tissue that make up compact bone        
    Heparin A naturally occurring anticoagulant Also used in laboratory tests for heavy metals    
    Hepatic To do with the liver        
    Hepatic portal vessel The blood vessel that carries blood from the intestines to the liver        
    Hinge joint A synovial joint that allows movement in only plane e.g. elbow        
    Histamine A substance secreted from white cells and platelets that is involved in the inflammatory response        
    Hock The joint (between the tarsals and metatarsals        
    Homoiothermic ‘Warm-blooded animals that regulate their body temperature        
    Hormone A secretion from an endocrine gland        
    Humerus The bone of the upper forearm between the scapula and the radius and ulna        
    Hyperglycemia Elevated blood glucose level        
    Hypertension High blood pressure        
    Hyperthermia High body temperature        
    Hypertonic Having an osmotic pressure higher than a solution with which it is compared        
    Hypotension Low blood pressure        
    Hypotonic Having an osmotic pressure lower than a solution with which it is compared        
    Ileum The terminal part of the small intestine        
    Immunity Being resistant to injury or invasion by microorganisms        
    Implantation The attachment of blastocyst to lining of uterus        
    Impotence The inability posterior copulate        
    Incisors The chisel-shaped ‘biting off teeth at the front of the mouth        
    Induced ovulation When ovulation is stimulated by mating as in cat and rabbit        
    Inferior Towards the lower part of the body. Not used in animals except, perhaps, higher apes        
    Infertility The inability carbohydrate. conceive or cause conception        
    Inflammation A localised protective response to tissue injury        
    Ingestion The taking in of food, liquids etc.        
    Inguinal To do with the groin        
    Inorganic Compounds that lack carbon        
    Insertion The attachment of a muscle tendon to a bone that moves        
    Inspiration Breathing in        
    Insulin A hormone produced by the pancreas. Decreases blood glucose levels        
    Intercostal muscles The muscles between the ribs.        
    Internal Away from the surface of the body        
    Internal Away from the surface of the body        
    Interstitial fluid Extracellular fluid surrounding the cells        
    Interstitial fluid Extracellular fluid surrounding the cells        
    Intervertebral disc A hole in a bone for passage of vessels or nerves        
    Intervertebral disc A pad of cartilage between the vertebrae        
    Intestinal juice Digestive secretion produced by glands in the lining of the small intestine        
    Intracellular fluid Fluid within the cells        
    Invertebrates Animals that do not posses a backbone or vertebral column        
    Ion A charged particle        
    Isotonic Having an osmotic pressure equal to that of a solution with which it is compared        
    Jejunum The small pouch that stores bile        
    Jejunum The middle portion of the small intestine        
    joint Point of contact between 2 bones        
    Keel The breast bone in birds        
    Keratin A protein found in epidermis, hair, feathers, hoofs etc.        
    Kidney The organ that produces urine        
    Lachrymal gland The tear gland of the eye        
    Lactation The secretion and ejection of milk by mammary glands|        
    Lacteal A lymphatic vessel within the villi of the small intestine        
    Lacuna A small hollow space        
    Lamellae Concentric rings of hard calcified material found in compact bone        
    Large intestine Part of the gut consisting of the colon, caecum, rectum and anal canal        
    Larynx The voice box        
    Lateral Away from the midline        
    Lens Transparent part of the eye that helps focus light rays on the retina        
    Leukocyte A white blood cell        
    Ligament Dense connective tissue that attaches bone to bone        
    Lipase Digestive enzyme that breaks down fats (lipids)        
    Lipid Fat        
    Liver The large organ caudal a neuron        
    Longitudinal Lengthwise slice of an animal or organ        
    Lordosis response Standing firm to pressure on the loin region        
    Lumbar Loin region of the back        
    Lumen A collection of cells artery, secrete substances        
    Lumen A space within an artery, vein, intestine or tube        
    Lung The organs of respiration        
    Luteinising hormone The hormone from the anterior pituitary gland that stimulates ovulation and development of corpus luteum        
    Lymph Tissue fluid that has entered the lymphatic system        
    Lymph node A structure that filters lymph and produces lymphocytes        
    Lymphatic capillary The closed ended microscopic vessel that collects lymph in tissues        
    Lymphatic tissue Specialised tissue that contains large numbers of lymphocytes        
    Lymphatic vessel A large vessel that carries lymph        
    Lymphocyte A white blood cell associated with the immune response        
    Lysosome A cell organelle that contains digestive enzymes        
    Macrophage A large phagocytic cell present in many tissues        
    Mammary gland The milk producing gland        
    Mandible The bone of the lower jaw        
    Marrow The soft sponge like material in the cavities of bone        
    Matrix The substance of a tissue in which the more specialised structures are embedded        
    Maxilla To do with smell        
    Medial Towards the midline        
    Mediastinum The tissue that separates the two sides of the lung        
    Medulla Inner part of an organ        
    Medulla oblongata The part of the brain stem or hind brain        
    Meiosis The type of cell division for production of gametes. Halves the number of chromosomes        
    Melanin The dark pigment in the skin and hair        
    Melatonin The hormone produced by the pineal gland        
    Membrane A thin, flexible sheet of tissue        
    Meninges The membranes covering the brain and spinal cord        
    Mesentery The membrane attaching the small intestine to the abdominal wall        
    Metacarpals A living form. One individual        
    Metastasis The distant spread of disease especially a malignant tumour from its site of origin        
    Metatarsals The five bones of the foot that connect the ankle” to the toes        
    Microfilaments  
    Microtubule A hollow rod of protein in the cytoplasm of all eukaryotic cells and in cilia, flagella, and the cytoskeleton        
    Microvilli The microscopic fingerlike projections from the membrane of the cells covering the villi of the small intestine        
    Microvilli The microscopic fingerlike projections from the membrane of the cells covering the villi of the small intestine        
    Middle ear The cavity in the skull between the eardrum and inner ear housing the auditory ossicles        
    Milk teeth The first set of teeth in a young animal        
    Minute volume The volume of air inspired or expired during a minute of normal tidal breathing        
    Mitochondrion The organelle in cell cytoplasm that produces energy        
    Mitosis The cell division for growth series repair. Produces 2 cells identical to parent and each othe        
    Molars The more posterior cheek teeth        
    Monocyte The largest leukocyte. It is phagocytic and has no granules in the cytoplasm        
    Monosaccharide The simplest carbohydrate. Also known as simple sugar        
    Morula The solid mass of cells produced by successive divisions of the fertilized ovum        
    Mucus A thick fluid secretion        
    Myelin The fatty insulating coating to an axon of a neuron        
    Nasal cavity The space just inside the nostril        
    Negative feedback Control in which the stimulus initiates actions that reverse or reduce the stimulus        
    Nephron The functional unit of the kidney        
    Nerve A bundle of nerve fibres        
    Nerve impulse The nerve “current’ that passes along a neuron        
    Neuron A nerve cell        
    Neuron A nerve cell        
    Neurotransmitter Molecules released at a synapse to the diaphragm        
    Neurotransmitter Molecules released at a synapse to transmit the nerve impulse from one neuron to the next        
    Neutral fat A fat or triglyceride. Biological compound consisting of three fatty acids linked to one glycerol molecule        
    Neutrophil White blood cell with granules in the cytoplasm involved in phagocytosis        
    Nictitating membrane The third eyelid in the cat, tuatara and crocodiles        
    Normal saline A 0.9% solution thyroid gland        
    Nuclear membrane The double layered membrane that surrounds the nucleus        
    Nucleolus The spherical body within the nucleus, containing RNA        
    Nucleus The spherical or oval body to the cell that contains the DNA        
    Nutrient        
    Oesophagus The hollow muscular tube connecting the pharynx with stomach        
    Olfactory To do with smell        
    Omasum Part of the modified stomach of ruminants with a folded inner surface        
    Open rooted teeth Teeth in which the root opening remains wide. They grow continuously e.g. the incisors of rabbits and rats        
    Optic Nerve The nerve carrying impulses from the retina of the eye the the brain        
    Orbit The bony cavity in the skull that holds the eyeball        
    Organ A structure with a specific function        
    Organelle A structure in the cell with a specific function        
    Organic A compound that contains carbon and hydrogen e.g. carbohydrates, lipids and proteins        
    Organism A living form. One individual        
    Origin The bones of the “hand”        
    Origin The attachment of a muscle to a bone enzyme secreted by the stomach wall        
    Osmosis The movement of water molecules across a semi permeable membrane from an area of high water concentration to an area of low water concentration        
    Osmotic pressure The pressure required to prevent water moving across a semi permeable membrane by osmosis        
    Ossicle A small bone        
    Ossification A solid contracting strand in the cytoplasm of cells that brings about cell contraction.        
    Ossification The formation of bone        
    Otolith A particle of calcium carbonate embedded in the membrane of the otolith organ of the inner ear        
    Oval window The small opening between the middle and inner ear        
    Ovarian cycle The series of events in the ovary associated with the maturation of the ovum        
    Ovarian follicle developing ovum with the epithelial tissues surrounding it        
    Ovary The female gonad that produces ova.        
    Ovulation The release of the ovum from the mature follicle of the ovary        
    Ovum The egg cell (plural: ova)        
    Oxyhaemoglobin Haemoglobin combined with oxygen        
    Oxytocin The hormone from the posterior pituitary gland. Stimulates milk “let down”        
    Palate The roof of the mouth        
    Palmar The “walking” surface of the front paw        
    Pancreas The organ lying along the caudal margin of the stomach. Has endocrine and exocrine functions        
    Pancreatic juice The digestive secretion produced by the pancreas        
    Parasympathetic division One of the two parts of the autonomic nervous system. Concerned with normal “at rest” activities        
    Parathyroid gland One of four small endocrine glands on the dorsal surface of the thyroid gland        
    Parathyroid hormone The hormone secreted from the parathyroid gland        
    Parathyroid hormone The hormone secreted from the parathyroid gland        
    Parotid gland One of sodium chloride        
    Parotid gland One of the paired salivary glands ventral to the ear        
    Parturition The act of giving birth        
    Patella To clean, straighten and fluff feathers        
    Pathogen A disease-producing organism        
    Pectoral A chemical substance in food that provides energy or assists various body processes        
    Pectoral To do with the chest the breast        
    Pelvic cavity The caudal portion of the abdominal cavity. Contains the bladder, colon and reproductive structures        
    Pelvic girdle        
    Pelvis The structure formed by the two hip bones, sacrum and coccyx        
    Pepsin A protein digesting enzyme secreted by the stomach wall        
    Pericardial cavity The small cavity between the two layers of the pericardial membranes        
    Pericardial cavity The small cavity between the two layers of the pericardial membranes        
    Pericardium The membrane that does not move        
    Pericardium The membrane that encloses the heart        
    Periosteum The tough connective tissue covering of a bone        
    Peripheral Located on the outer part of the body        
    Peripheral nervous system Bone part found in the spaces of the nervous system composed of the cranial and spinal nerves        
    Peristalsis The successive muscular contractions along the wall of the gut        
    Peritoneum The membrane that lines the abdominal cavity and covers the abdominal organ        
    Permanent teeth The second set of teeth that persist through life        
    Peyer’s Patches Large clusters of lymph nodules found in the wall of the small intestine        
    pH A symbol that indicates the acidity or alkalinity of a solution        
    Phagocytosis The process by which cells ingest particles and bacteria        
    Phalanges The bones of the “fingers” and “toes”        
    Pharynx The throat        
    Phospholipid bilayer The arrangement of phospholipids molecules in two layers        
    Phospholipids Molecules that make up the double layer of biological membranes        
    Photoreceptor A receptor that detects light        
    Photosynthesis The making of organic molecules by plants using energy from the sun        
    Physiology The science that deals with the functions of an organism and its parts        
    Pineal gland The gland situated in the brain that secretes melatoni        
    Pinna The projecting part of the external ear        
    Pinocytosis The process by which cells ingest liquid        
    Pituitary gland The endocrine gland lying under the caudal surface of the brain attached to the hypothalamus by a stalk        
    Pivot joint A synovial joint where a peg of bone articulates with a ring of bone as in dim light        
    Placenta The special structure through which the exchange of materials between the foetus and mother occurs        
    Plantar The “walking” surface of the hind paw        
    Plantigrade locomotion        
    Plasma Breeding fluid that surrounds the blood cells        
    Plasma membrane The outer membrane surrounding the cell        
    Platelets Cell fragments in the blood essential for clotting        
    Pleura Membranes that cover a lungs and line the walls of the chest and diaphragm        
    Pleural cavity The space between the two layers of semen        
    Plexus A network of nerves        
    Poikilothermic ‘Cold-blooded’ animals whose body temperature varies, to a large extent depending on the environment        
    Polysaccharides A carbohydrate formed from up to a thousand monosaccharides        
    Preen To clean, straighten and fluff feathers        
    Premolars The kneecap        
    Premolars Small more anterior cheek teeth        
    Progesterone The hormone produced by the corpus luteum        
    progesterone The bone of the upper jaw        
    progesterone The female sex hormone produced by ovaries        
    Prolactin A hormone produced by the anterior pituitary gland        
    Prostate gland The gland caudal to bladder in males        
    Proteases Enzymes that split proteins into amino acids        
    Protein The synovial joint where the humerus joins the scapula        
    Proximal The bony structure formed by the hip bones, sacrum and coccygeal bones        
    Proximal Nearer to the body or to the point of origin        
    Pulmonary To do with the lungs        
    Pulp cavity The cavity within the crown and neck of a toot        
    Pulse The series of waves of high pressure blood passing along an artery        
    Pupil The hole in the centre at the large intestine        
    Pus Dead white blood cells        
    Pyloric sphincter The ring of smooth muscle between the stomach and the small intestine        
    Radius The shorter bone of the forelimb between the humerus and the “wrist”        
    Receptor A specialized cell that responds to specific sensory stimuli such as touch,pressure, light etc.        
    Red marrow Bone marrow found in the spaces of spongy bone.Makes red blood cells        
    Reflex A fast automatic response to a stimulus        
    Reflex arc Consists of receptor, sensory, relay and motor neurons with effector        
    Refraction Bending of light as it passes from one medium to another        
    Relaxin The hormone secreted by the placenta and ovaries that eases the joint between the right and left pelvis arteries, dilates the cervix for birth        
    Renal To do with the kidney        
    Renal pelvis The cavity in the centre of the kidney        
    Renal pyramid The cone shaped structure in kidney medulla        
    Renal system The body system involving the kidneys        
    Reticulum The part of the modified stomach of ruminants with honeycomb of raised folds on its inner surface        
    Retina Scale like        
    Ribosome The organelle in the cell that makes proteins        
    Rickets A bone disorder caused by inadequate vitamin D        
    Rod The photoreceptor on the hind leg        
    Rostral Towards the joint between the atlas and axis        
    Rostral Towards the muzzle        
    Rumen The first and largest compartment of the modified stomach of ruminants.It houses and the microorganisms        
    Ruminant An animal with or rumen e.g. sheep, cow, camel        
    Rumination Chewing the “cud”        
    Sacrum The triangular bone formed from fused sacral vertebrae.Located between the two hipbones        
    Sagittal plane Plane that divides the body into left and right portions        
    Sagittal section Lengthwise slice of an animal or organ        
    Saliva The secretion from the salivary glands        
    Salivary amylase Locomotion involving placing the whole surface of the foot on down the ground as in humans and bears        
    Salivary amylase The starch digesting enzyme in saliva        
    Saturated fat A fat containing saturated fatty acids        
    Scapula The shoulder blade        
    Sciatic nerve The large nerve that passes down the hind leg        
    Sclera The fibrous outer coat of eyeball        
    Seasonal breeding Breeding confined to certain seasons of the year        
    Sebaceous gland An exocrine gland in the dermis of the skin associated with a hair follicle        
    Sebum The waxy secretion from a sebaceous gland        
    Secondary sex characteristic A characteristic that develops at sexual maturity. e.g. large body size of males, manes in lions        
    Secretion The production or release of a fluid from a gland        
    Semen The fluid discharged at ejaculation of male. Consists of sperm and fluid        
    Semi-permeable membrane A membrane that allows some substances to cross more easily than others        
    Semicircular canals The membranous fluid filled canals containing receptors for equilibrium        
    Semilunar valve The valve guarding the entrance to the aorta or the pulmonary artery        
    Seminal vesicle A gland that secretes a component of semen        
    Seminiferous pleura        
    Seminiferous tubule The tightly coiled duct in the testis where sperm joint        
    Sensory neuron        
    Serum Plasma minus its clotting proteins        
    Sesamoid bones Small bones usually found in tendons        
    Shock Reduced cardiac output resulting in failure to deliver adequate oxygen and nutrients to the body        
    Shoulder The synovial joint where the humerus joins the scapula        
    Sinus An organic compound consisting in a bone especially in the bones of carbon, hydrogen, oxygen and nitrogen. Made up of amino acids        
    Sinus An air cavity in a bone especially in the bones of the face or skull        
    Skeletal muscle Tissue specialized for contraction with striated fibres. Attached to the bones of the skeleton        
    Skull The skeleton of the head        
    Small intestine The long tube of the gut that begins at the stomach and ends at the large intestine        
    Smooth muscle Tissue specialized for contraction with spindle shaped non striated fibres        
    Smooth muscle Tissue specialized for contraction with spindle shaped non striated fibres        
    Soft palate The posterior portion of the iris of the eye        
    Soft palate The posterior portion of the roof of the mouth        
    Solution One or more substances dissolved in a liquid        
    Specific gravity The measure of the density of a liquid or solid, as compared with that of water.        
    Sperm duct The tube that carries sperm from the epididymis to the urethra. Also called the vas deferens        
    Spermatic cord The structure in the male reproductive system attached to the testis that carries the vas deferens, arteries, veins, etc.        
    Spermatozoon Normal mature sperm cell        
    Sphincter A ring-like muscle of controls movement along a body passage or orifice        
    Spinal cord The mass of nerve tissue in the vertebral column        
    Spinal nerve One of the nerves that originate in left the spinal cord        
    Spleen The large lymphatic organ near the stomach that stores blood and produces lymphocytes        
    Spongy bone The inner layer of bone; found at the ends of long bones less dense than compact bone        
    Squamous Scale like        
    Starch The inner coat of the eyeball. Nerve calls here (rods and cones) respond to light ray        
    Starch The storage polysaccharide in plants consisting of many glucose molecules        
    Sterile Free from any living micro organisms        
    Sternum The breastbone        
    Stifle The joint between the femur and the tibia on the hind leg        
    Stimulus Any change in the retina, specialized for vision in dim light        
    Stimulus Any change in the environment capable of initiating a nerve impulse        
    Stomach The large baglike part of the gut between the oesophagus and the small intestine        
    Striated muscle Striped or skeletal muscle        
    Subcutaneous Beneath the skin        
    Submandibular gland The salivary gland beneath the tongue        
    Substrate A substance on which an enzyme acts        
    Sulcus A groove of the lungs        
    Superficial Nearer to the surface of        
    Suture An immoveable joint in the skull        
    Sympathetic division One of the two subdivisions of the autonomic nervous system concerned with reacting to emergency situations        
    Synapse The junction between two neurons        
    Synapse The junction between two neurons        
    Synovial joint A fully moveable joint        
    Synovial joint A fully moveable joint        
    System An association of organs that have a common function, e.g. digestive system, respiratory system        
    Systemic circulation The blood circulation from the left ventricl through the aorta to all the organs of the body and back foetus to the heart        
    Systole The phase of the heartbeat involving contraction of the ventricles        
    Systolic blood pressure One of two tubes that connect the kidney with the bladder        
    Target cell A cell whose activity is affected by a particular hormone        
    Target produced        
    Tarsals Thebones of the “ankle”        
    Tendons A neuron that carries a nerve impulse towards the central nervous system        
    Tendons The tough cord of fibrous connective tissue that connects muscles to bones        
    Testis The male gonad that produces sperm        
    Testosterone The hormone produced by the cells between the seminiferous tubules of the testis        
    Thoracic cavity The chest cavity that contains the heart and lungs        
    Thorax The part of the body between the neck and the diaphragm        
    Thymus gland The organ dorsal to the sternum that is essential to the immune response        
    Thyroid gland  
    Thyroxine The hormone secreted by the thyroid gland        
    Tibia The medial bone of the lower hind limb        
    Tidal breathing Normal at rest breathing        
    Tidal volume The volume of air breathed in or out in any one “at rest” breath        
    Tissue A group of similar cells        
    Tissue fluid Plasma that has left cava One of two large blood vessels that return blood to the capillaries the flowed into the spaces between the cells of the tissues; also known as intercellular fluid or interstitial fluid        
    Total lung capacity The sum of the tidal volume, inspiratory reserve, expiratory reserve and residual volume of the lungs        
    Trachea The windpipe        
    Trachea The windpipe        
    Transverse A crosswise slice of an animal or depression between the convolutions of the brain        
    Transverse A crosswise slice of an animal or organ        
    Triceps The muscle that extends from the shoulder to cord        
    Triglycerides A biological compound consisting of three fatty acids linked to one glycerol molecule. A fat        
    Trunk        
    Tympanic membrane The thin transparent membrane of connective tissue between the external ear, canal and the middle ear. Also called the eardrum        
    Ulna The longer bone of the forelimb between the humerus and the “wrist”        
    Umbilical cord The cord containing arteries and vein that attaches the foetus to the placenta        
    Unguligrade locomotion Locomotion on the “fingernails” as in horses and pigs        
    Urea The soluble excretory product produced when excess amino acids (from proteins) are broken down by the body        
    Ureter One of two tubes body        
    Urethra The blood pressure during passage of the pulse        
    Urethra The duct from the bladder to the exterior of the body        
    Uric acid An insoluble excretory product produced when excess amino acids(from proteins) are broken down by the body        
    Urinalysis The analysis functioning of urine        
    Urine The fluid produced by the kidneys        
    Uterus The hollow muscular organ in females where the foetus develops        
    Vagina The muscular, tubular organ in the female where sperm are deposited during copulation        
    Vagus nerve The cranial nerve that controls the muscles that bring about swallowing,the muscles of the heart, airways, lungs, stomach and intestines        
    Vane The flat part of a feather emerging from the shaft; there are two vanes per feather        
    Vas deferens The duct that conducts the sperm from the epididymis to the urethra        
    Vascular To do with blood        
    Vaso dilation The increase in size of the channel down a blood vessel        
    Vasoconstriction The decrease in size of the channel down a blood vessel        
    Vein A blood vessel that carries blood towards the heart        
    Velvet The endocrine gland with lobes on either side of the trachea        
    Velvet The tissue layer that covers antlers        
    Vena cava One of two large blood vessels that return blood to the heart        
    Ventral Nearer the belly of the animal than        
    Ventricles The caudal chambers of the heart        
    Venule A small vein        
    Vertebral canal The channel that encloses and protects the spinal cord        
    Vertebrates Animals elbow responsible for extending the forearm        
    Vertebrates Animals that have have a backbone or vertebral column        
    Vesicles Small, intracellular membrane-bound sac        
    Vestibular organ The part of the body of balance the fore and hind limbs are attached        
    Vestibular organ The organ of balance – semicircular canals and otolith organ        
    Villus (pl. villi) A projection from the lining of the small intestine to help absorb digested food molecules        
    Viscera The organs in the abdominal and pelvic cavities        
    Visceral skeleton Bones formed in the organs of the body        
    Viscosity The connect or kidney with the bladder        
    Viscosity The thickness or stickiness of a liquid        
    Vital capacity The sum of the inspiratory and expiratory reserve volumes and the tidal volume        
    Vital capacity The volume of the air expired when a maximum expiration follows a maximum inspiration        
    Vitamin An organic molecule necessary in minute quantities for the proper functioning of the chemical processes in the body        
    Vitreous Humor The fluid in the posterior chamber of the eye        
    White matter Masses of myelinated axons located in the brain and spinal cord        
    Yellow marrow Bone marrow that is yellow with fat; found at the ends of long bones        
    Zona pellucida The tough layer surrounding the ovum        
    Zygote Single cell resulting from the union of the sperm and egg        
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