Anatomy and Physiology of Animals/Glossary/Book version


Word Meaning
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
Aqueous humor The watery fluid that fills the anterior chamber of the eye
Arteriole A small, almost microscopic, artery
Artery A blood vessel that carries blood away from the heart
Articulation The point of contact between bones. Where they move against each other
Appendage A structure attached to the body
Aqueous humor The watery fluid that fills the anterior chamber of the eye
Arteriole A small, almost microscopic, artery
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.

A joint. Point of contact between 2 bones

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 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 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


Word Meaning
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 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


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
Coccyx The tail bones
Coccygeal vertebrae The vertebrae of the tail
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 that surrounds and protects the brain
Crop The bag-like structure at the base 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 and doves Parents regurgitate it to feed their young
Cross section Crosswise slice of an animal or organ
Cryptorchidism Undescended testes
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 A nerve cell process that carries the nerve impulses towards the cell body
Dental formula The formula that describes the numbers of the different kinds of teeth
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 The shaft of a long bone
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 passive process of movement of molecules from a region of high concentration to one of low concentration
Digestion The mechanical and physical breakdown of food
Digitigrade locomotion Locomotion on the “fingers” as in cats and dogs
Dilate To expand or swell
Diploid Having a double set of chromosomes one maternal, one paternal
Directional terms Terms that describe the locations of structures in relation to other structures or locations in the body
Disaccharides Double sugar, consisting of two joined monosaccharides
Distal Farther away from the trunk of the body or point of origin
Diuretic A chemical that reduces Antidiuretic hormone production and increases urine volume
Dorsal Nearer the back of the animal than
Duodenum First part of the small intestine


Word Meaning
Echolocation The use of high frequency sound like sonar and radar by animals (i.e. whales and bats) to locate objects in the surrounding environment
Effector A muscle or gland that responds to a motor neuron impulse
Egestion The elimination of indigestible waste products from the body
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 a thousandfold greater than that of a light microscope
Element Any substance that cannot be broken down to any other substance
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 A substance that increases the speed of a chemical reaction
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 The remnant of epiphyseal plate at end of long bone
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
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
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 of a situation is

continually fed back to the central control region

Femur The long bone between the pelvis and 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
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 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 A hole in a bone for passage of vessels or nerves
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


Word Meaning
Gall bladder The small pouch that stores bile
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 A 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 of birds. In seed eating birds it contains pebbles and its muscular walls help grind the food
Gland A collection of cells that secrete substances
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 A 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 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 one 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


Word Meaning
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 to 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 to 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
Interstitial fluid Extracellular fluid surrounding the cells
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 middle portion of the small intestine


Word Meaning
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


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

Dense connective tissue that attaches bone to bone

Lipase Digestive enzyme that breaks down fats (lipids)
Lipid Fat
Liver The large organ caudal to the diaphragm
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 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


Word Meaning
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 The bone of the upper jaw
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 The bones of the “hand”
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 A solid contracting strand in the cytoplasm of cells that brings about cell contraction.
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
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 and 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
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 of sodium chloride
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 in the cell that contains the DNA
Nutrient A chemical substance in food that provides energy or assists various body processes


Word Meaning
Excessive accumulation of fluid in the body tissues
Oesophagus The hollow muscular tube connecting the pharynx with stomach
The female sex hormone produced by ovaries
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 to 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 attachment of a muscle to a bone that does not move
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 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 The 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
Parotid gland One of the paired salivary glands ventral to the ear
Parturition The act of giving birth
Patella The kneecap
Pathogen A disease-producing organism
Pectoral To do with the chest or breast
Pelvic cavity The caudal portion of the abdominal cavity. Contains the bladder, colon and reproductive structures
Pelvic girdle The bony structure formed by the hip bones, sacrum and coccygeal bones
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
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 The part 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 the joint between the atlas and axis
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 Locomotion involving placing the whole surface of the foot on the ground as in humans and bears
Plasma The 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 the lungs and line the walls of the chest and diaphragm
Pleural cavity The space between the two layers of the pleura
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 more anterior cheek teeth
Progesterone The hormone produced by the corpus luteum
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 An organic compound consisting of carbon, hydrogen, oxygen and nitrogen. Made up of amino acids
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 of the iris of the eye
Pus Dead white blood cells
Pyloric sphincter The ring of smooth muscle between the stomach and the small intestine


Word Meaning
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 and 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

and dilates the cervix for birth

Renal To do with the kidney
Renal pelvis The cavity in the centre of the kidney
Renal pyramid A 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 The inner coat of the eyeball. Nerve calls here (rods and cones) respond to light ray
Ribosome The organelle in the cell that makes proteins
Rickets A bone disorder caused by inadequate vitamin D
Rod The photoreceptor in the retina, specialized for vision in dim light
Rostral Towards the muzzle
Rumen The first and largest compartment of the modified stomach of ruminants.It houses the microorganisms
Ruminant An animal with a 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 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
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 tubule The tightly coiled duct in the testis where sperm are produced
Semi-permeable membrane A membrane that allows some substances to cross more easily than others
Sensory neuron A neuron that carries a nerve impulse towards the central nervous system
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 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
Soft palate The posterior portion of the roof of the mouth
Solution One or more substances dissolved in a liquid
Specific gravity A 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 A mature sperm cell
Sphincter A ring-like muscle that 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 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 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 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 or depression between the convolutions of the brain
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
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 to the heart
Systole The phase of the heartbeat involving contraction of the ventricles
Systolic blood pressure The blood pressure during passage of the pulse
Synapse The junction between two neurons
Synovial joint A fully moveable joint


Word Meaning
Target cell A cell whose activity is affected by a particular hormone
Tarsals The bones of the “ankle”
Tendons A 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 The endocrine gland with lobes on either side of the trachea
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 the capillaries and 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
Transverse A crosswise slice of an animal or organ
Triceps The muscle that extends from the shoulder to the elbow responsible for extending the forearm
Triglycerides A biological compound consisting of three fatty acids linked to one glycerol molecule. A fat
Trunk The part of the body to which the fore and hind limbs are attached
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 that connect the kidney with the bladder
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 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
Vasoconstriction The decrease in size of the channel down a blood vessel
Vaso dilation The increase in size of the channel down a blood vessel
Vein A blood vessel that carries blood towards the heart
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 that have a backbone or vertebral column
Vesicles Small, intracellular membrane-bound sac
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 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