Friday, 26 April 2024, 10:57 AM
Site: VetLogic - E Learning and training for Vet Nurses
Course: VetLogic - E Learning and training for Vet Nurses (VetLogic)
Glossary: Glossary with audio assistance
A

Absorption

the movement of a fluid or a dissolved substance across a cell membrane, for example the soluble products of digestion pass through the mucus membrane of the small intestine into the blood stream

Acid/base balance

maintenance of the normal pH within the body systems

Acromegaly

excess growth of bones after the epiphyses have closed, caused by excess secretion of growth hormone

Actin

a contractile protein found in muscle fibres

Active transport

the movement of molecules or ions through transport proteins across a cell membrane, against their concentration gradient. The process requires energy from ATP

Acute

a disease that has a rapid onset, short duration and pronounced clinical signs

Ad libitum feeding

feeding performed with freedom. Sometimes called free-choice or Ad lib

Addison's disease

disease caused by insufficient adrenocortical hormones; hypoadrenocorticism

Additive

a substance purposely put into food to give a desirable characteristic (e.g. color, flavor, texture, resistance to spoilage etc)

Adipose tissue

fat tissue in the body

Aerobic

requiring oxygen for life and growth

Aerobic respiration

the enzymatic release of energy from the oxidation of organic compounds in living cells in a process requiring oxygen

Afferent nerve fibres

carry nerve impulses towards the central nervous system

Agonal gasp

a terminal breathing pattern where the animal appears to be gasping for breath

Agonist

something which increases a response

Albumin

the most abundant plasma protein. Principally responsible for maintenance of circulating blood volume by preventing too much water leaving the capillaries by osmosis.

Allele

one of two or more different forms of a gene. Different alleles of a gene occupy the same locus on a pair of homologous chromosomes.

Alleles

these are alternative forms of a gene, showing different options for the same gene e.g. red, black, white coat coloring. Each has a specific place or ‘locus’ on the chromosome.

Alopecia

A partial or complete loss of hair in areas where it is normally present

AMTRA

Animal Medicines Training Regulatory Authority

Anabolic reaction

a reaction in which chemical substances are built up and energy is used

Anaemia

a deficiency in the number of circulating red blood cells or haemoglobin concentration in the blood

Anaerobic

not requiring oxygen

Anaerobic respiration

the partial oxidation of organic compounds in the cell to release energy, in a process which does not require oxygen

Anastomosis

an artificial or naturally occurring connection between two structures, which are normally separate, for example between blood vessels or loops of intestine

Androgens

a group of male sex hormones e.g., testosterone

Anion

a negatively charged particle

Anisocoria

Pupils that are not symmetrical in size. i.e. one pupil may be constricted and the other dilated.

Anode

a positively charged electrode to which electrons are attracted

Anorexia

loss of appetite for food

Antagonist

something which prevents or decreases a response

Anthroponosis

a disease which can be spread from humans to animals

Antibody

a globular protein or immunoglobulin, made by plasma cells and secreted into the plasma in response to a specific antigen, in order to destroy and eliminate the antigen from the body

Antidotes

specific reversing agent for a poison

Antigen

a substance that is foreign to the body and stimulates an immune response

Antiperistalsis

movement of food material up the digestive tract. This is in the opposite direction to peristalsis.

Antisepsis

the prevention of sepsis (presence of pathogenic organisms or their toxins in the blood or body tissues)

Antiseptic

a chemical use to control, prevent or destroy pathogens present on living tissues/skin

Anuria

lack of urine output

Anxiolysis

decreased level of anxiety

Apnoea

Arrhythmia

an abnormal heart rhythm

Artefact

any mark on a radiograph which decreases the quality

Artery

blood vessel carrying blood away from the heart

As fed basis

the concentration of a nutrient in the food as it is fed to the animal, which includes the water content of the food

Ascites

excess fluid in the abdominal cavity

Asepsis

freedom from infectious material

Aseptic

the complete absence of bacteria, viruses or fungi that could cause disease. Asepsis is the ideal situation for the performance of surgical or other invasive procedures, and is achieved by sterilisation techniques

Asexual reproduction

reproduction which involves only one parent and produces offspring which are identical to the parent

Ash

the residue left after combustion of the food - generally the mineral content

Asystole

no electrical activity in the heart – a ‘flat line’ on the ECG

Atom

smallest particle capable of existing on its own or as molecules when in combination with other atoms

ATP

adenosine triphosphate, a high energy phosphate molecule used to store and release energy for work within the body

Auscultation

a technique used for listening to the sounds of the body with the use of a stethoscope, for example the heart beat and respiratory sounds within the thoracic cavity

Autonomic nervous system

part of the peripheral nervous system that supplies stimulation to the cardiac and smooth muscles and the glands of the body, involved in unconscious control

Autosomes

all the chromosomes within the nucleus of the cell except the sex chromosomes

Autotransformer

prevents fluctuations in the mains voltage and ensures constant 240 volts supplied to the X-ray machine

AVM GSL

Authorised Veterinary Medicine - General Sales List

Azotaemia

increased levels of nitrogenous by-products in the bloodstream

B

Back cross to recessive

identification of the recessive carrier can be done by a test mating with a known homozygous recessive animal. This will determine if the other animal is carrying a recessive gene. If they are carrying a recessive gene, then a percentage of the animals show the recessive characteristic. If they are not a recessive carrier then the recessive characteristic will not appear. We will use the Labrador as an example at the end of the glossary.

Back scatter

scattered radiation which travels in the opposite direction to the primary beam

Bacteraemia

the presence of bacteria in the blood

Bacteria

prokaryotic single-celled organism. Ranges in size from 0.3µm-10 µm

Bactericidal

an agent that kills bacteria

Bacteriostatic

prevents bacteria from multiplying but does not kill them

Barrier nursing

utilisation of protective clothing and isolation to prevent transmission of disease from hospitalised animals

Basophil

type of granular white blood cell

Biliary

pertaining to the bile duct

Bilirubin

yellow green bile pigment which results from the breakdown of red blood cells

Bilirubinuria

the presence of bilirubin in the urine

Binary fission

the replication of bacteria

Biological vectors

the organism undergoes part of its lifecycle inside the host

Blood brain barrier

a semipermeable membrane that keeps circulating blood separate from cerebrospinal fluid and the brain

Blood plasma

fluid surrounding the blood cells and transported by the blood-vascular system

Bolus

a ball of chewed food bound together with saliva that is formed in the mouth by the action of the tongue

Brachycephalic

having a short, broad skull, e.g. boxers, bulldogs, pugs, Persian cats, lionhead rabbits. These animals tend to have overlong soft palates, excessive soft tissue in their oral cavity and pharynx, smaller tracheal diameters than expected, and narrow nares.

Bradycardia

a slower than normal heart rate

Bradypnoea

a slower than normal respiratory rate

Breathing

Buffer

a substance which is able to resist change in the pH of a solution so that the pH remains constant

Buffer solution

a solution which will maintain body pH due to the release or absorption of hydrogen ions to balance any loss or gain. Carbon dioxide only partially dissolves in solution, and this means that it can act as a buffer. If more hydrogen is present then it will be combined with bicarbonate and converted to water and carbon dioxide. Water will be lost through the kidneys and carbon dioxide will be lost in exhaled air. Alternatively, if metabolic alkalosis is present, then carbon dioxide will be combined with water and converted to bicarbonate and hydrogen ions, to maintain the pH.
C

Calculus

stone like deposits of mineral salts found in hollow organs or on the teeth. In the urethra they can result in blockage of the passage of urine.

Calling

persistent yowling exhibited by the female cat (queen) during the pro-oestrus period of the oestrous cycle

Canaliculus

a space containing a cytoplasmic process of an osteocyte in bone tissue, or a space between rows of cells in the liver along which bile flows

Capillary refill time

time taken for blood capillaries to refill after flow in them has been disrupted in some way

Carcinogenic

any agent or substance that can cause tumour formation and cancer

Cardiac

pertaining to the heart

Carnivore

meat-eating animal

Carrier

an individual who has a copy of a recessive gene that is not expressed because of heterozygosity, but the gene can be passed on to the next generation, alternatively, an individual, infected with a pathogen, but not showing any symptoms of disease.

Carriers

convalescent carrier: animal which has had a disease and recovered

Carrion

decaying flesh

Cassette

a light-proof container which holds X-ray film and intensifying screens in close contact

Catabolic reaction

a reaction in which chemical substances are broken down and energy is released

Cathode

negatively charged electrode which produces electrons

Cation

a positively charged particle

Caudal fermenter

herbivorous animal whose main microbial fermentation takes place in the large intestine

Cell

a structure bound by a plasma membrane, containing cytoplasm and organelles; the basic structural and functional unit of all living organisms.

Central Nervous System

the part of the nervous system that consists of the brain and the spinal cord

Centriole

an organelle composed of microtubules, that is involved in the formation of the spindle during mitosis

Centromere

the part of the chromosome to which spindle fibres attach during cell division

Cerebrospinal fluid

clear fluid produced in the choroid plexus of the ventricles of the brain. It is found in the brain and spinal cord. 

Chlamydia

bacterial agent that causes Chlamydia infection in cats

Chloroplasts

organelles, found in plant cells, which contain chlorophyll (green pigment). They are the sites of photosynthesis.

Chondrocyte

cell found in cartilage

Chromatid

two identical chromosomes, joined together by a centromere, formed during the interphase of the cell cycle

Chromatin

material within the nucleus of a eukaryotic cell which consists of DNA and histone proteins

Chromosome

thread-like structure made up of DNA and histones, containing a series of genes, found in the nucleus of a eukaryotic cell

Chronotrope

A drug that increases the rate of cardiac contraction

Chyle

fatty liquid absorbed from the small intestine by lymphatic capillaries known as lacteals

Chylothorax

lymphatic fluid in the pleural cavity

Chyme

partially digested food with an acid pH expelled from the stomach

Cilia

short hair-like structures found on the surfaces of some cells and organisms; used for either propelling trapped material out of the body or for locomotion

Cisternal puncture

obtaining a sample of cerebrospinal fluid from the cisterna magnum

Clotting time

time taken for blood to clot naturally

Codominance

both the alleles of a gene are expressed equally in the phenotype even though they may be different

Coitus

the act of mating

Collimation

the process of altering the size of the primary beam using a light beam diaphragm (LBD)

Colloid

a fluid where solid molecules are suspended in a liquid (but invisible to the naked eye). In fluid therapy, colloid fluids contain large molecules that remain in the circulation and therefore are plasma volume expanders.

Colonisation

the formation of compact population groups of the same type of microorganism

Commensal

living on or within another organism, and deriving benefit without harming or benefiting the host individual; an organism that causes neither harm nor benefit to the host

Compound follicle

hair follicle which consists of a primary hair follicle and several secondary hair follicles

Concentration gradient

the change in the concentration of a substance from one area to another

Conceptus

embryo or fetus plus the surrounding membranes and placenta

Conditionally essential nutrient

a nutrient that is normally not essential but becomes so, due to certain physiological or pathological conditions resulting in relative deficiency

Conditioned reflex

a reflex action which has been modified in response to experience or learning. For example, a dog may salivate when it sees its owner remove a tin opener from a drawer.

Conjugation

bacterial mating

Connective tissue

tissue that binds structures together, made up of cells and an intercellular matrix and its functions include support, protection and repair

Constipation

infrequent or difficulty passing of faeces

Contagion

the transmission of disease from one individual to another

Contagious

capable of being transmitted between animals by direct or indirect contact

Contamination

the soiling or making inferior by contact or mixture

Contrast

the difference in radiographic density between adjacent areas on a radiograph

Contrast media

substances which are introduced into the patient to increase or decrease radiopacity and contrast during an X-ray

Contrast study

a radiographic procedure which improves the contrast of the area under examination

Controlled drug

a drug whose use and possession  is controlled by legislation

Coprophagia

eating faeces

Coupage

percussion of the chest using cupped hands to aid removal of secretions

Cranial fermenter

herbivorous animal whose main microbial fermentation takes place in a modified stomach

Cranium

the skull containing the brain

Crossed grid

two parallel grids at right angles to each other

Crystalloid

a fluid containing small molecules which move quickly from the circulation

Cumulative

to build up

Cushing's disease

disease caused by excess adrenocortical hormones; hyperadrenocorticism

Cystitis

inflammation of the bladder

Cytokinesis

the division of the cytoplasm of a cell following division of the nucleus

Cytoplasm

a jelly-like material that surrounds the nucleus of a cell and contains most of the cell's organelles

D

Dead space

the air within the respiratory tract that never reaches the alveoli within the lungs and so does not undergo gaseous exchange

Deamination

the breakdown of excess amino acids in the liver, whereby the amine group is removed and converted to ammonia and eventually urea before excretion

Deciduous dentition

teeth seen in the young animal soon after birth. These are shed after a few months and are replaced by the permanent teeth.

Defecation

act of passing feces from the rectum

Definition (radiographic)

the quality of the radiograph which is affected by density, contrast and sharpness

Deglutition

the act of swallowing

Density (radiographic)

the degree of blackening of the radiograph

Dermal papilla

structure situated at the base of the hair follicle containing nerves and blood vessels, which supply nutrients necessary for hair growth

Dermis

layer of dense connective tissue lying beneath the epidermis

Desiccation

the process of losing moisture or “drying out” when exposed to air

Detergent

a chemical that disperses and removes soil, organic material and greasy residue from surfaces as well as reducing surface tension and increase the penetrating ability of water. This is a process that is important in allowing disinfectants to penetrate the pathogens underneath. Some disinfectants have their own detergent properties (eg the halogens – bleach and iodine, quaternary ammonium compounds).

Developer

a chemical solution which converts exposed silver bromide crystals into silver metal within the emulsion during processing

Diarrhoea

production of faeces that contain an excess amount of water

Diastema

a space between teeth. There is a natural space in the jaw of rodents and herbivores where canine teeth would be found in other species.

Diastole

relaxation stage of the cardiac cycle. The term applies to both atrial and ventricular relaxation.

Diffusion

the net movement, as a result of random motion of its particles, of a substance from an area of high concentration to an area of low concentration

Digestion

the process by which food materials are broken down into small soluble chemical units

Dilated pupils

Dilated pupils (mydriasis) are when the black center of your eyes are larger than normal. The condition may be caused by dilating eye drops from an eye exam, the side effects from a drug/medication or traumatic injury.

Diploid cells

cells with the full number of chromosomes, each in pairs. These include most cells within the animal’s body.

Diploid number

the number of chromosomes (2n) found in the nucleus of all cells except gametes which are haploid cells

Disinfectant

a chemical used to control, prevent and destroy pathogens present on inanimate objects - although it is not usually active against bacterial spores. The process does not necessarily kill all micro-organisms, but reduces then to a level acceptable for a defined purpose, for example a level which is considered not harmful to health. (Note, the difference between “disinfectants” and “antiseptics” which are applied to living tissues.)

Disinfection

the removal or inactivation of pathogenic micro-organisms but not necessarily of bacterial spores

Disinhibited

to loose inhibitions and become exited

Diuresis

increased amount of urine produced

Diuretics

drugs used to increase the production of urine by the kidneys and so reduce water retention in the body

DNA

deoxyribonucleic acid, the genetic material found inside the nucleus of the cell

DNA gyrase

enzyme that controls coiling and uncoiling of DNA

DNA polymerase

enzyme that catalyses the synthesis of new DNA molecules

Dominant gene

a gene whose characteristics are always present in the phenotype, in homozygous and heterozygous individuals. It is represented with a capital letter, e.g. B.

Dosemeter

a device for monitoring exposure to X-rays

Drug schedule

classification of drugs within the Misuse of Drugs Regulations 2001

Dry matter

food residue after being heated to remove all the water

Dwarfism

smaller than normal size

Dysecdysis

abnormal shedding of the skin of reptiles

Dysphagia

difficulty swallowing

Dyspnoea

Dystocia

difficult parturition; difficulty giving birth

Dysuria

difficulty in passing urine

E

Ectoparasite

a parasite that lives on the outside of the host

Efferent nerve fibres

carry nerve impulses away from the central nervous system

Electrolyte

a liquid that contains ions (salts) such as sodium and potassium

Electromagnetic spectrum

Radiation which possesses electrical and magnetic properties

Electron

a negatively charged particle

Embolism

a clot, air bubble or debris (embolus) which is carried in the blood stream from one point in the circulation to lodge at another point

Embryo

stage of development in the zygote in which the external and internal structures are developing

Emesis

vomiting

Emetic

Something that induces vomiting

Emollients

substances such as liquid paraffin that will aid expulsion from the digestive tract

Emulsification

process where fat particles are broken down into smaller globules suspended in a liquid

Emulsion

a liquid in which droplets of other liquids are suspended, but the liquids do not mix

Endemic

a disease peculiar to or that occurs constantly in certain localities or populations

Endobronchial

positioned in the bronchus

Endocardium

the innermost layer of the heart

Endocrine gland

ductless gland whose secretions (hormones) reach their target organ via the bloodstream

Endocytosis

the movement of a substance, in bulk, into a cell by the formation of vesicles from the plasma membrane

Endoparasite

a parasite that lives inside the host

Endothermic

regulation of body temperature by internal heat production

Endotoxin

a toxic substance released by bacteria when the organism dies

Endotracheal

positioned in the trachea

Energy

the ability to do work; all the body's activities require energy which is provided by the consumption of food containing chemical energy

Enteral feeding

uses the gastrointestinal tract to provide nutrition

Enzootic

a disease peculiar to or that occurs regularly in certain localities or populations

Enzyme

a protein which is able to act as a catalyst within a living organism

Eosinopaenia

reduced numbers of circulating eosinophils in the blood

Eosinophil

type of granular white blood cell

Eosinophilia

increased number of circulating eosinophils in the blood. May be seen in cases of allergy or parasite infestation.

Epidermis

the tough outer protective layer of the skin

Epistasis

a gene that suppresses the activity of other genes at other loci

Epithelium

tissue composed of cells that lines the internal and external surfaces of the body; plural is epithelia

Eructation

a belch; oral ejection of gas or air from the stomach

Eruption of teeth

Process by which teeth break through the gum to appear in the jaw

Erythema

reddening of the skin

Erythroblasts

immature red blood cells

Erythrocytes

red blood corpuscles or cells

Erythropoiesis

the formation of red blood cells

Erythropoietin

hormone produced by the kidney which stimulates the bone marrow to produce new red blood cells

Eukaryote

a cell with cytoplasm containing a membrane-bound nucleus in addition to other organelles

Excretion

the process by which waste materials are removed from the body

Exocrine gland

gland whose secretions reach their target organ by means of a duct

Exocytosis

the movement of a substance, in bulk, out of a cell by fusion of vesicles containing the substance with the plasma membrane

Exothermic

regulation of body temperature by the external environment rather than by internal metabolism

Exotoxin

a toxic substance released by the living bacteria

Expiration

the process by which gas is expelled from the lungs - breathing out

Expiratory capacity

Expiratory reserve volume

the extra volume of air forced out of the lungs, above that of normal tidal volume after a forced expiration

External respiration

the exchange of gases between the atmospheric air and the blood. Also called breathing.

Exteroreceptors

sensory cells that receive information from the environment outside the body

Extracellular fluid (ECF)

fluid found outside the cells

Exudate

fluid with a high protein and cell content that has seeped out of the blood vessels and is found in tissues, usually as a result of inflammation

F

Facilitated diffusion

the diffusion of a substance through protein channels in a cell membrane

Fat

a mixture of lipids, mainly triglycerides, that is solid at room temperature. In mammals fat is deposited within the body as adipose tissue.

Feedback

control mechanism by which the output of a system is regulated by the product or response that system produces

Feline Lower Urinary Tract Disease (FLUTD)

condition of cats characterized by dysuria, haematuria, pollakiuria and/or urethral obstruction

Fermentation

the anaerobic conversion of organic compounds (especially carbohydrates) to simpler compounds such as volatile fatty acids (SCFAs). Occurring in the caecum and colon, it is an essential part of the digestive process.

Fetus

stage of development in the zygote in which all the organs are fully developed

Fibre

the portion of the food that cannot be broken down by the intestinal enzymes of mammals

Fibrin

derived from fibrinogen, an insoluble protein which forms a mesh across areas of damaged capillaries that traps cells and platelets to form a clot

Fibrinogen

one of the  plasma proteins; involved in the blood clotting mechanism

Filament

the coil of wire at the cathode which produces electrons when heated

Film focal distance (FFD)

the distance between the focal spot in the tube head and the X-ray film on the table. Usually 75-100 cm.

First filial generation

the offspring produced from a parental cross, denoted as F1 in genetic notation

Fixer

a chemical used in radiographic processing, which dissolves unexposed silver bromide crystals and causes the film's emulsion to harden

Flagella

long cell appendages used for locomotion in some micro-organisms. Singular - flagellum.

Flexi-cassette

a flexible structure which contains intensifying screens and X-ray film

Fluoroscopy

imaging technique that uses X-rays to view real-time images

Focal spot

the actual small area on the target that the electrons hit

Focussed grid

a grid where the lead strips are progressively more angled towards the edges

Focussing cup

a structure located at the cathode in the tubehead, made of molybdenum, which focuses the electron beam towards the anode

Fogging

an overall appearance of grey on a radiograph which decreases contrast

Fomite

an inanimate object that has been contaminated and can act as a source of infection

Functional residual volume

the volume of air left in the lungs after normal expiration

G

Gamete

specialized germ cell. Either sperm or ovum. Contains the haploid (n) number of chromosomes.

Ganglion (pl.ganglia)

collection of nerve cell bodies in the peripheral nervous system

Gaseous exchange

the movement of gases between an organism and its environment; often takes place across a specialized surface, for example the alveoli of the lungs

Gastritis

Inflammation of the stomach

Gene

unit of inheritance. Short units of DNA which codes for a particular protein or polypeptide.

Genetic damage

harmful effects of X-rays which affect the genes of the reproductive cells

Genetics

the science of inheritance. Physical characteristics and abilities are largely determined by ‘genetic makeup’. In the 1860s, Mendel carried out studies which showed that each organism has physical traits which correspond to invisible elements within the cell.

Genotype

the genetic make-up of an animal

Geriatric

Elderly; the term is often used when an animal reaches or exceeds 75% of its expected lifespan

Gestation

the period of development of the young from fertilization to birth

Giantism

larger than normal size

Gingivitis

inflammation of the gingiva or gums

Glial cell

type of cell found in nervous tissue which provides metabolic and structural support for neurons

Glucosuria

the presence of glucose in the urine

Gluten

the protein found in wheat and other cereal grains

Glycogenolysis

breakdown of glycogen stored in the liver to release glucose

Glycolipids

fats that bind to one or more chains of sugars

Glycoproteins

proteins that bind to one or more chains of sugars

Golgi apparatus

a stack of membrane-bound, flattened sacs responsible for the modification and export of proteins from the cell

Gonad

male (testis) or female (ovary) organ responsible for producing the gametes

Gonadotrophin

any of the hormones that stimulate the gonads

Gram negative

classification of bacteria; Gram negative bacteria do not retain the crystal violet stain in a Gram stain

Gram positive

classification of bacteria; Gram positive bacteria retain the crystal violet stain in a Gram stain

Grid

a device for absorbing scattered radiation and decreasing fogging

Grid cut-off

underexposed areas at the edges of a radiograph due to absorption of more of the primary beam by the grid

Grid factor

the amount by which the mAs has to be increased when using a grid

Grid lines

fine lines which are apparent on a radiograph when a stationary grid is used

Grid ratio

an indicator of the grid's efficiency at absorbing scattered radiation, it is the height of the lead strips in relation to the distance between them

Guard hair

the longest, thickest hairs in an animal's coat, forming the topcoat. They protect the undercoat and are often waterproof.

Gustation

scientific name for the sensation of taste

H

Haematocrit

a test to measure the red blood cells as a percentage of the total volume of blood. Haematocrit is the calculated number, using an analyser, whereas packed cell volume (PCV) is derived from manual measurement.

Haematopoiesis

formation of blood and blood cells

Haematuria

presence of blood in the urine

Haemoglobinuria

presence of haemoglobin in the urine

Haemorrhage

loss of blood

Haemothorax

blood in the pleural cavity

Hair bulb matrix

part of the hair that is situated at the end of the follicle and produces the cells of the hair

Halitosis

bad breath

Haploid cell

cell with half the number of chromosomes, and no pairs. These include the gametes (i.e. sperm and ova).

Haploid number

a single set of chromosomes (n) found in the nuclei of gametes, this is half the number of chromosomes found in the nuclei of all other eukaryotic cells

Haversian canal

channel in the center of a Haversian system containing nerves, blood vessels and lymph vessels

Haversian system

a unit of bone structure in which the bone cells are arranged in concentric circles

Healthy carriers

animals that have not shown clinical signs of disease

Hepatic

pertaining to the liver

Herbivore

plant-eating animal

Hering Breuer reflex

reflex pathway between pulmonary stretch receptors and the brain that prevents overinflation of the lungs

Heterozygous

having two different alleles of a gene

High voltage transformer

increases the incoming mains voltage (240 V) to thousands of volts (kV)

Histology

the study of normal healthy tissues using a microscope

Histones

proteins that bind to DNA in eukaryotic cells

Homeostasis

the maintenance of a constant internal environment

Homozygous

having two identical alleles of a gene

Hormone

secretion produced by an endocrine gland and carried to its target organ by means of the blood

Hydrophilic

water loving

Hydrophobic

water hating

Hyperadrenocorticism

disease caused by excess adrenocortical hormones; also known as Cushing's disease


Hypercalcaemia

increased blood calcium level

Hypercapnia

increased carbon dioxide levels - end tidal and in the blood

Hyperglycaemia

increased blood glucose level

Hyperkalaemia

increased blood potassium level


Hyperpnoea

increase in the depth of breathing

Hyperreflexia

excessive or exaggerated reflex action

Hypertension

higher than normal blood pressure

Hyperthermia

higher than normal body temperature

Hyperthyroidism

disease caused by excess thyroid hormone in the blood

Hypertonic

a fluid with a higher osmotic pressure than that with which it is compared (usually plasma)

Hypertonic fluid

has a higher concentration of solutes than blood plasma and causes water to be drawn out of the cells into the circulation

Hyperventilation

excessive rate and depth of ventilation

Hypervolaemia

abnormal increase in blood volume

Hypoadrenocorticism

disease caused by insufficient adrenocortical hormones; also known as Addison's disease

Hypocapnia

decreased carbon dioxide levels - end tidal and in the blood

Hypoglycaemia

decreased blood glucose level

Hypoproteinaemia

decreased plasma protein level in the blood

Hyporeflexia

weaker than normal reflex action

Hypotension

lower than normal blood pressure

Hypothermia

lower than normal body temperature

Hypothyroidism

disease caused by a lack of thyroid hormone in the blood

Hypotonic

a fluid with a lower osmotic pressure than that with which it is compared (usually plasma)

Hypotonic fluid

has a lower concentration of solutes than blood plasma and causes water to enter the cells

Hypoventilation

inadequate ventilation

Hypovolaemia

abnormal decrease in blood volume

Hypoxaemia

decreased level of oxygen in the blood

Hypoxia

decreased level of oxygen in the body tissues

I

Immunity

ability to resist specific types of disease

Inappetence

Lack of appetite

Inbreeding

breeding from two animals that are closely related, e.g. brother and sister

Inbreeding depression

loss of health and increasing weakness brought about by inbreeding over successive generations

Incubation period

the time between an individual animal meeting a source of infection and developing clinical signs of disease

Infection

the invasion and multiplication of micro-organisms in body tissues

Infectious

capable of causing disease between animals

Inflammation

the body's reaction to injury and infection characterized by pain, swelling and heat

Ingestion

the taking in of food

Ingredient

a raw or processed foodstuff used in manufacturing food

Inorganic

a substance that is not derived from a living organism and does not contain hydrocarbon groups

Inotrope

drug that increases the force of cardiac contraction

Insensible losses

water losses from the body that cannot be accurately measured

Inspiration

the act of taking air into the body - breathing in

Inspiratory capacity

Inspiratory reserve volume

the extra volume of air taken into the lungs, above that of the normal tidal volume after a forced inspiration

Intensifying screens

structures within a radiographic cassette which fluoresce when struck by X-rays

Intercalated neuron

a neuron that lies between a sensory and a motor neuron but which in itself has neither sensory nor motor functions

Internal respiration

the exchange of gases between the blood and the tissues. Also called tissue respiration.

Interoceptors

sensory cells that detect stimuli from within the body, for example, information pertaining to blood pressure

Interspecific hybrid

result of crossing two animals from different species

Interstitial fluid

fluid found between the cells but not within the vascular system

Intracellular fluid (ICF)

fluid found inside the cells

Intramuscular

into a muscle

Intrathecal

injection where drugs are administered into the cerebrospinal fluid

Intravenous

into a vein

Intussusception

telescoping of part of the intestine into itself causing an obstruction

Inverse square law

the intensity of the radiation beam is inversely proportional to the square of the distance from the source i.e. X-rays diverge increasingly, the further they travel from the tube head, and their intensity falls

Ion

a charged particle

Isotonic

a fluid with the same osmotic pressure as that with which it is compared (usually plasma)

Isotonic fluid

has the same concentration of solutes as blood plasma; water neither enters nor leaves the cells and remains in equilibrium 

J

Jejunum

part of the small intestine between the duodenum and the ileum

K

Keratolytic

an agent that breaks down keratin of the stratum corneum

Ketonuria

presence of ketones in the urine

Kilocalorie

the amount of energy required to raise the temperature of 1 g of water by 1 degree Celsius

Kilovoltage (kV)

the potential difference applied to the X-ray tube head which is responsible for accelerating the electrons towards the anode

L

Labile tissues

Cells continue to divide even once the organism has finished growing, repair by regeneration is usually possible.

Lactation

production of milk from the mammary glands

Lactose

one of the sugars derived from milk

Lacunae

spaces within the matrix of bone tissue containing cells

Laryngoscope

an aid to visualisation for endotracheal intubation. The equipment consists of a blade which depresses the tongue, and a light source for illumination.

Larynx

part of the respiratory tract between the pharynx and trachea. It is made up of cartilages,  ligaments and muscles and lined with mucus membrane.

Latent image

an invisible image on X-ray film following exposure but before processing

Lead

a dense metal which is efficient at absorbing X-rays

Lethal gene

gene that produces a characteristic that is incompatible with life

Leukaemia

a disease where there are increased numbers of immature and abnormal white blood cells (leukocytes)

Leukocyte

white blood cell

Leukocytosis

an abnormal increase in the number of white blood cells in the blood

Licensed drug

Medication which has been approved to be given to animals

Light Beam Diaphragm (LBD)

a device fitted to the tube head for altering the size of the primary beam

Line breeding

similar to inbreeding but involves breeding from family lines that are not closely related e.g. grandparents or cousins. The aim is to increase the likelihood of the desired characteristics, but reduce the chances of those that are not desired.

Linked genes

gene that are so close together on the same chromosome that they move with each other into the same cells during meiosis and do not act independently

Locus

the position of a gene on a chromosome

Lordosis

excessive inward curvature of the spine. In female cats, it is a behaviour pattern exhibited during the oestrous cycle, where they raise the tail and hindquarters.

Low voltage transformer

decreases the incoming mains voltage (240 V) to provide small current to the filament and prevent overheating

Lymph

excess tissue fluid carried in the lymphatics. Has similar constituents to plasma but contains fewer plasma proteins.

Lymphocyte

type of agranular white blood cell, responsible for the production of antibodies

Lysosomes

structures found within the cytoplasm of cells which contain digestive enzymes; responsible for removal of cell debris

M

Magnification

the number of times greater an image is than the actual object

Malnutrition

abnormal nutrition, usually nutritional deficiency but may also mean  excess of nutrition

Mange

skin conditions caused by a variety of mites

Mastication

chewing

Maximum Permissible Dose (MPD)

an amount of radiation exposure whichis considered no more hazardous than that which could be encountered on a day to day basis

Mechanical vector

the organism is only carried by the host and does not undergo any development inside the host

Megakaryocytes

large cells, found in the bone marrow, that break up to form platelets, which are important in the clotting mechanism of blood

Meibomian glands

modified sebaceous glands present in the eyelids which produce an oily secretion, which helps to prevent the eye from drying out. Also called tarsal glands.

Meiosis

cell division involved in ova and sperm production. Four haploid cells are produced, each with half the number of chromosomes than the parent cell.

Melanocyte

cell in the skin that produces and contains the pigment called melanin

Mendel's First Law of Inheritance - the Law of Segregation

at meiosis only one of the two alleles is transmitted to each gamete

Mendel's Second Law of Inheritance - the Law of Independent Assortment

each pair of genes is inherited without being influenced by the presence of other genes

Metabolic acidosis

acidic plasma pH due to a metabolic process. A common example of this is diarrhoea, resulting in acidosis.

Metabolic alkalosis

less acidic plasma pH due to a metabolic process. A common example of this is acute vomiting resulting in a loss of hydrogen ions from the stomach. Chronic vomiting will result in metabolic acidosis due to a loss of bicarbonate from intestinal contents.

Metabolism

the sum of the physical and chemical changes that take place in living organisms. These changes include both synthesis (anabolism) and breakdown (catabolism) of substances in the body.

Micro-organism

an organism too small to be seen by the naked eye; a microscopic organism

Microtubules

protein structures that help cells maintain their shape and are involved in cell movement and cell structure

Micturition

the act of expelling urine from the bladder

Milk teeth

see deciduous teeth

Milliamperes (mA)

combination of the mA and exposure time which dictates the number of X-rays produced during an exposure

Miosis

constriction of the pupil

Mitochondria

membrane-bound organelle that is the site of aerobic respiration in the cell

Mitosis

the division of the nucleus that results in two diploid cells with exactly the same number and type of chromosomes as the parent cell

Mixed nerve

contains both sensory and motor fibres

Modified transudate

transudate with a high protein and cell content, as in inflammation. Eventually, modified transudate may become exudate

Monocyte

type of agranular white blood cell

Monogastric

stomach with only one compartment

Monosynaptic reflex

a reflex that only involves a single set of synapses

Motor fibres

nerve fibres that carry impulses away from the central nervous system

Multicellular

Organisms that consist of more than one cell

Multiparous

give birth to more than one offspring; litter-bearing

Murmur

abnormal heart sound created by alteration of blood flow through the heart

Mutualistic bacteria

an association between organisms of two different species in which each member benefits

Mycoplasma

prokaryotic organism that does not have a cell wall

Mydriasis

Dilation of the pupil

Myelin sheath

the insulating, fatty layer, produced by Schwann cells, that surrounds the axon in some nerves

Myelography

diagnostic imaging procedure, whereby contrast agent is injected into the cerebrospinal fluid

Myosin

contractile protein found in muscle fibres

N

Neonate

a newborn animal

Nephrotic syndrome

a collection of symptoms seen in end-stage renal failure, including protein loss in the urine, low blood serum albumin levels and oedema

Neuromuscular blocking agent

drug that prevents the transmission or reception of impulses from motor nerves to skeletal muscle and therefore produces muscle paralysis

Neurons

the primary cells in nervous tissue. They transmit information as electrical signals around the body.

Neutropaenia

reduced numbers of circulating neutrophils in the blood

Neutrophil

type of granular white blood cell, also known as polymorphonucleocyte

Neutrophilia

increased numbers of circulating neutrophils in the blood, e.g. in the presence of infection

NFA VPS

Non-Food Animal - Veterinary, Pharmacist, Suitably Qualified Person

Non-screen film

individually wrapped pieces of X-ray film that are not placed in a cassette. Generally used for dental studies due to the flexibility of the film.

Normothermia

normal body temperature

Nuclear envelope

the double membrane surrounding the nucleus in eukaryotic cells. It separates the contents of the nucleus (DNA in particular) from the rest of the cell.

Nuclear pores

small gaps in the nuclear envelope which allows passage of materials in and out of the nucleus

Nucleic acid

large molecules composed of smaller units of nucleotides; includes both RNA and DNA

Nucleolus

small structure inside the nucleus of a cell, where ribosomes are manufactured

Nucleotide

any of a group of molecules that link together to form the basic structural unit of DNA and RNA

Nucleus

1. collection of nerve cell bodies within the central nervous system. 2. a membrane-bound organelle, found in all eukaryotic cells, which contains most of the cell's genetic material. 3. the positively charged centre of an atom.

Nutraceutical

functional foodstuff, including fortified food and dietary supplements, that may have health benefits

Nutrient

a component of food with a metabolically useful function

Nystagmus

rapid involuntary movement of the eyes, either in a horizontal or vertical direction


O

Oedema

excessive accumulation of fluid in the tissues or body cavities; often results in swelling of the area

Oestrogen

female sex hormone secreted by the ovary

Olfaction

scientific name for the sensation of smell

Oliguria

reduced urine output

Omnivore

animal that eats both plants and meat

Organ

a group of tissues that perform a particular function

Organic substance

a substance that is derived from a living organism or contains hydrocarbon groups, for example fats and carbohydrates

Orthopnoea

breathing in an upright position, usually standing; the elbows are abducted to minimise compression of the chest wall

Osmoregulation

the maintenance of optimal osmotic pressure by controlling water and salt content of body fluids

Osmosis

the movement of water from an area of low concentration to one of high concentration through a semipermeable membrane, in order to equalise the concentrations on each side of the membrane

Osmotic pressure

the pressure needed to prevent osmosis from occurring; depends on the number of particles in a solution

Osteoblast

bone-forming cell

Osteoclast

cell that breaks down bone

Osteocyte

bone cell

Ototoxicity

toxic to the ear, specifically the vestibulcochlear system (inner ear)

Outbreeding

breeding from two animals that are not related

Oxidation

1. reaction in which oxygen molecules are added to a chemical substance. 2. loss of electrons.
P

Palpation

examination using the hands to feel part of the body, for example the pulse in an artery or organs in the abdomen

Pandemic

an epidemic which occurs all over the world

Panleukopenia

decreased number of all white blood cells circulating in the blood

Papule

a small, solid bump that rises from the skin

Paracellular

between cells; paracellular transport is the route substances travel between cells 

Parallel grid

the most basic type of grid where the lead strips are parallel to each other

Parasite

an agent that lives with and at the expense of an animal host

Parasympathetic nervous system

Paratenic host

an intermediate host where no development of the parasite occurs; the paratenic host is ingested by the final host for completion of the life cycle

Parenteral

route of administration other than gastrointestinal tract

Parenteral nutrition

nutrition that is given intravenously

Parturition

the process of giving birth

Passive transport

movement of molecules down a concentration gradient without energy use

Pathogen

a disease-producing organism

Pathogenesis

 the origin and development of disease

Pathogenic

capable of causing disease

Penetrating power

the ability of X-rays to penetrate tissue i.e. their energy affected by kV setting

Penumbra

zone of unsharpness or blurring on a radiograph

 

Peripheral nervous system

part of the nervous system outside the brain and spinal cord

Peristalsis

waves of muscular contractions that occur in tubular structures to move contents forwards, e.g. food and other ingested material is moved along the gastrointestinal tract towards the anus. Peristalsis also occurs in the uterine tubes and the ureters.

Permanent dentition

teeth that develop in the jaw after the deciduous teeth have been shed, and remain for the whole lifetime

Permanent tissues

Cells have very limited capacity for regeneration and as such repair by replacement is the most likely response to injury.

pH

literally, ‘per hydrogen’. pH refers to the acidity of a substance - one with a low pH has a high concentration of hydrogen ions and is acidic. One with a high pH has a low concentration of hydrogen ions and is alkaline.

Phagocytosis

ingestion of bacteria by cells such as neutrophils and monocytes

Pharmacology

study of drugs, including their use, effects and mode of action

Phenotype

physical appearance of an animal

Phlebitis

Phospholipid

a lipid that contains a phosphate group. Phospholipids are the main form of lipid in cell membranes.

Photosynthesis

The process by which green plants make carbohydrates such as sugar, using water, carbon dioxide, and sunlight

Pinocytosis

the process by which fluid is taken into the cell

Plasma

the fluid part of blood that remains when a sample of blood is separated in a centrifuge

Plasma membrane

the membrane that surrounds a living cell; it consists of a double layer of phospholipids with embedded proteins

Platelets

also called thrombocytes, these are small particles derived from megakaryocytes, found in plasma, that are involved in the clotting mechanism of blood

Pleurisy

infection and inflammation of the pleural membranes. May be exudative or dry.

Pneumonia

infection and inflammation of the lungs

Pneumothorax

air in the pleural cavity

Polydipsia

excessive thirst and intake of fluid

Polyphagia

excessive appetite and intake of food

Polysynaptic reflex

a reflex that involves several intercalated neurons in the pathway

Polyuria

excessive excretion of urine

POM V

Prescription Only Medicine - Veterinary

POM VPS

Prescription Only Medicine - Veterinary, Pharmacist, Suitably Qualified Person

Potter-Bucky

a parallel grid which moves rapidly from side to side during the exposure

Precursor

substance from which another is formed by chemical reaction

Prehension

picking up or grasping food

Prescribing cascade

Legislation controlling which medications can be given to animals

Preservative

a substance added to another to protect against spoilage during storage

Primary beam

the beam of X-rays which emerge from the tube head during an exposure

Primary follicle

opening on the surface of the skin through which a single guard hair grows

Prokaryote

a cell that does not possess a true nucleus, nor does it have many or any other cell organelles, e.g. bacteria and viruses

Proprioceptors

sensory cells that receive information about the position of limbs or the tension of muscles and tendons within the body

Prostatitis

inflammation of the prostate gland

Protein

a large complex molecule made up of one or more chains of amino acids

Proteinuria

presence of protein in the urine

Prothrombin

a type of plasma protein, required for normal clotting of blood

Protozoa

eukaryotic single-celled organisms

Pruritus

itching

Pseudo-focussed grid

a type of grid where the lead strips are parallel to each other but are progressively shorter towards the edge of the grid

Pulmonary

pertaining to the lungs

Pulse rate

the number of times a pulse is felt in one minute; this should be the same as the heart rate

Pyaemia

the presence of a pus-forming organism in the blood

Pyothorax

pus in the pleural cavity

R

Radiograph

a visible record on film of the pattern of X-rays passing through a patient

Receptors

sensory cells that receive information from the environment, in the form of a stimulus, and transfer this information to the brain or spinal cord as a nerve impulse

Recessive gene

a gene which is only expressed in the phenotype when no dominant allele is present

Reflex action

a fast, automatic response to a stimulus

Reflex arc

the pathway taken by an action potential leading to a reflex action

Renal

pertaining to the kidneys

Reservoir

a source of infection

Residual volume

the volume of air left in the lungs after the deepest possible expiration; the air that is always in the lungs

Resolution

the ability to distinguish between two objects very close together; the higher the resolution of an image the greater the detail that can be seen

Respiration

breathing; exchange of gases - oxygen and carbon dioxide

Respiratory acidosis

a decrease in pH of blood, ECF and CSF, due to hypoventilation and accumulation of hydrogen ions and carbon dioxide

Respiratory alkalosis

an increase in pH of blood, ECF and CSF, due to hyperventilation and loss of hydrogen ions and carbon dioxide

Respiratory rate

the number of breaths in one minute

Respiratory tract

the conducting pathway of air in and out of the body, from the nose to the pulmonary alveoli

Rhythmic segmentation

muscular contractions which break up and mix the food within the gastro-intestinal tract. These movements do not push the food along the tract.

Ribosome

cellular organelle that is the site of protein synthesis

Rickets

abnormal ossification during growth due to a deficiency of vitamin D

Rickettsia

A micro-organism that requires other cells for growth but which uses oxygen and possesses a cell wall

Rough endoplasmic reticulum

system of membrane-bound tubes and sacs containing ribosomes that functions in the synthesis of proteins

Ruminant

animal in which the stomach is multi-chambered, the largest chamber of which is the rumen

S

Salts

synonym for electrolytes

Saphrophite

an organism living and feeding on dead and putrefying matter

Sarcolemma

membrane surrounding a skeletal muscle fibre

Satiety

the satisfaction of appetite

Scattered radiation (scatter)

X-rays which have collided with matter, lost some energy and changed direction

Screen film

X-ray film which is placed in a cassette containing intensifying screens prior to use

Sebaceous

relating to glands found in the dermis of the skin, that produce sebum

Seborrhoea

Excessively oily skin, due to overproduction of sebum

Sebum

an oily substance produced by sebaceous glands in the skin

Second filial generation

offspring produced by breeding from two individuals from the F1 generation; denoted as F2 in genetic notation

Sensory fibres

nerve fibres that carry impulses towards the central nervous system

Septicaemia

the presence of pathogenic bacteria in the blood

Serum

the fluid that separates from blood when it clots

Sex chromosomes

the pair of chromosomes that determine the gender of an individual

Sex-limited gene

gene that influences a characteristic seen in either the male or the female

Sex-linked gene

gene carried on one of the sex chromosomes

Sharpness

the clarity of structures on a radiograph

Shift to the left

increased numbers of immature white blood cells circulating in the blood

Sinus

cavity within a bone or other tissue; paranasal sinuses are air-filled cavities in the bones of the face

Smooth endoplasmic reticulum

system of membrane-bound tubes and sacs that is involved in the synthesis of lipids

Smooth muscle

muscle tissue with no striations that is not under voluntary control

Solubilised

a substance is dissolved in another

Solute

the ionic component of an electrolyte

Solvent

the liquid component of an electrolyte

Somatic cells

the classification of every cell in the body except for the germ (reproductive) cells

Somatic damage

damage to the tissues caused by X-rays which becomes apparent during the individual's lifetime

Somatic motor nerve

nerve fibres that carry impulses from the central nervous system to a somatic structure

Somatic sensory nerve

nerve fibres that carry impulses from a somatic structure to the central nervous system

Somatic structures

structures that lie in the skin and the musculoskeletal system

Special sense organs

organs that have evolved to house the exteroreceptors of the body

Sphincter

muscular ring that controls flow in and out of an organ

Spinal nerves

any of the pairs of nerves that arise from the spinal cord

Stable tissues

Repair by regeneration is sometimes possible.

Steatorrhoea

the presence of excess fat in faeces

Stercobolin

bile pigment found in faeces and responsible for the characteristic colour of faeces

Sterilisation

the destruction of all microorganisms and their spores

Striated muscle

muscle fibres that have striations and are under voluntary control; also called skeletal muscle

Subcutaneous

under the skin

Subcutis

the deepest layer of skin composed mainly of adipose tissue

Sudoriferous gland

gland in the dermis of the skin that secretes sweat

Sympathetic nervous system

Syncope

fainting

Systole

contraction stage of the cardiac cycle. The term applies to both atrial and ventricular contraction.

T

Tachycardia

a faster than normal heart rate

Tachypnoea

Tactile hair

long thick hairs such as the whiskers in cats and dogs, that are highly sensitive to pressure and touch and which provide sensory information about the environment

Target

the area of the anode which electrons bombard during an exposure

Temporary teeth

see deciduous teeth

Teratogenic

an agent that is damaging to a developing embryo or fetus

Thermionic emission

the process where electrons are released from the filament when it is heated

Thermoluminescent dosemeter (TLD)

a device for monitoring exposure to X-rays

Thrombocytes

Tidal air

the air that passes in and out of the lungs in one breath

Tidal volume

the volume of air that passes in and out of the lungs in one breath during normal respiration

Timer

a device that controls the length of exposure

Tissue

a group of similar cells that all perform a particular function

Tissue respiration

Titrate

to give small incremental doses of a drug to effect

Tonsilitis

inflammation of the tonsils

Topical application

treatment applied to the skin or mucous membranes to act on these sites

Total lung capacity

the volume of air breathed in with maximum inspiration or breathed out with maximum expiration; it is the vital capacity plus the residual volume

Toxaemia

the presence of toxins in the blood

Transamination

the conversion of one amino acid into another by the liver

Transcellular fluid

the portion of extracellular fluid formed by active cellular secretions

Transcellular route

the path substances take to travel across the cells

Transformer

alters the mains voltage

Transport vector

one that can shed the organism at any time

Transudate

excessive accumulation of fluid with a low protein and cell content, not inflammatory in nature, as seen, for example, in cardiac disease

Tube head

the structure that is responsible for producing X-rays

Tungsten

the metal that is used at the filament and the target in the X-ray tube head

U

Unconditioned reflex

a reflex that is automatic and unconscious

Unicellular

composed of a single cell

Uniparous

gives birth to one neonate

Upper motor neuron

a motor neuron that starts in the brain and transfers information to the spinal cord

Uraemia

increased level of urea in the blood

Urethritis

Urinary incontinence

inability to control the flow of urine out of the body

Urinary tenesmus

straining to pass urine

Urolith

a calculus in the urinary tract

Urolithiasis

the formation of uroliths, calculi or 'stones' in the kidney, bladder or urethra

V

Vacuole

a cavity or vesicle in the cytoplasm of a cell usually containing fluid

Vapour

gas phase of an agent that can be compressed to a liquid by pressure, e.g. isoflurane and sevoflurane

Vasoconstriction

narrowing of blood vessels

Vasodilation

widening of blood vessels

Vein

blood vessel carrying blood towards the heart

Viraemia

the presence of viruses in the blood

Virulence

the degree of pathogenicity

Virus

an microscopic infectious agent that requires the cells of a host animal (or plant) in which to reproduce

Visceral motor nerve

nerve fibres that carry impulses from the central nervous system to an organ

Visceral peritoneum

thin layer of epithelial tissue covering all the organs in the peritoneal cavity

Visceral sensory nerve

nerve fibres that carry impulses from an organ to the central nervous system

Visceral system

any of the body systems made up of internal organs, e.g. digestive and respiratory systems

Vital capacity

volume of air that can be exhaled after the deepest possible inspiration; it is the usable air in the respiratory system

Vitamin

a number of unrelated organic compounds essential in small amounts for normal metabolism

VMD

Veterinary Medicines Directorate

VMP

Veterinary Medicinal Product

Vocalization

making sounds

Vomitus

matter from the stomach that returns against the normal direction of peristalsis and may be ejected from the mouth by vomiting

W

Water potential

the tendency of a solution to lose water molecules

Weaning

the act of separating the young from their nursing mother, as they become dependant on other foodstuffs for their nourishment

Withdrawal period

the set time that must pass, after giving a medicine to a food-producing animal, before it can be slaughtered for meat or its products used for human food

Wool hair

the fine soft hairs that make up the undercoat
X

X-ray

a type of high energy electromagnetic radiation

Z

Zoonosis

a disease that can be passed from animals to people. Plural: zoonoses

Zygote

structure formed from the fusion of two gametes and which contains the diploid number of chromosomes