Anaemia = A deficient quantity of red blood corpuscles.

Anion = A negatively charged ion; e.g. Chloride (Cl-).

Anorexia = Loss of appetite, may be partial or complete.

Antibody = Blood protein produced in the lymphoid tissue that counteracts the effects of bacterial antigens or toxins.

Aspiration Pneumonia = Accumulation of infected material in the lungs from inhalation; this is a complication that may arise from forced feeding.

Buffer = A substance that acts to prevent change in the concentration of another chemical; bicarbonate is the chief buffer of blood.

Burette = A measuring device which may be incorporated into a giving set to allow greater accuracy of infusion.

Capillary refill time = The time taken for blood to return to the capillaries following occlusion; the gum is a suitable site to test CRT.

Cation = A positively charged ion; e.g. Potassium (K+).

Central Venous Pressure = A measurement of the pressure recorded by the introduction of a catheter into the right atrium of the heart.

Colloid = A solution containing large particles which do not easily leave the vascular space therefore expanding plasma volume; often referred to as plasma expanders.

Crystalloid = A sodium based electrolyte solution of a composition similar to that of plasma water which readily passes through cell membranes to equilibrate with the intracellular fluid.

Dehydration = Excessive bodily fluid loss; may be as a result of primary water depletion (e.g. lack of drinking water) or mixed water and electrolyte depletion (e.g. losses resultant from persistent vomiting or diarrhoea).

Dysponoea = Laboured breathing.

Electrolyte = A substance which dissociates into ions when dissolved in a solution.

Enzyme = A protein which acts as a catalyst to a chemical reaction without undergoing a chemical change itself.

Extra Cellular Fluid = The fluid component of the body that surrounds the cells. It comprises one third of the body's water and consists of interstitial fluid, plasma water and transcellular fluid.

Exudate = Serous fluid discharge from the corpuscle walls.

Febrile Reaction = A reaction related to fever (pyrexia).

Haematuria = The presence of blood in the urine.

Haemolytic Anaemia = Excessive red blood cell destruction resultant from antibody formation in the blood; causes include certain drugs, toxaemia and severe burns.

Hypraldosteronism = Condition in which a tumour of the pituitary gland causes over-secretion by the adrenal cortex; characterised by obesity and abnormal hair distribution. Also known as Cushing's disease.

Hyperkalcaemia = Abnormally high blood potassium levels.

Hypernaetraemia = Abnormally high blood sodium levels.

Hypertonic = Solution of higher osmolarity than that of the fluids of the body.

Hypokalcaemia = Abnormally low blood potassium levels.

Hyponatraemia = Abnormally low blood sodium levels.

Hypoplastic Anaemia = Anaemia resultant from the imperfect development of erythrocytes.

Hypoproteinaemia = Deficiency of blood proteins.

Hypotonic = Solution of lower osmolarity than that of the fluids of the body.

Hypovolaemia = Reduction in the circulating blood volume.

Hypovolaemic Shock = Shock resultant from the reduction of circulating blood following haemorrhage or severe burns.

Interstitial Fluid = Extra cellular fluid located in the tissue spaces responsible for bathing the body cells; it acts as an intermediary between the cells and the blood.

Intracellular Fluid = The largest fluid component of the body; fluid found within the cells.

Isotonic = Solution of equal osmolarity to that of the fluids of the body.

Malignant Hyperthermia = Serious increase in body temperature; a condition that may arise during general anaesthesia.

Metabolic Acidosis = Retention of fixed acid or loss of alkali.

Metabolic Akalosis = Fixed acid loss or alkali retention.

Oedema = Excess fluid in the body tissues.

Oliguria = Inability to pass urine.

Osmoreceptor = A specialised nerve cell responsible for monitoring the osmotic pressure of the blood and extracellular fluid.

Osmosis = The movement of pure solvent (water) from an area of low concentration to one of a higher concentration through a semi-permeable membrane.

Packed Cell Volume = The percentage of whole blood composed of erythrocytes; also known as haematocrit.

Peritonitis = Inflammation of the peritoneum; usually acute.

pH = Per hydrogen; the negative logarithmic expression of the concentration of hydrogen ions in solution.

Plasma = The fluid portion of the blood in which the corpuscles are suspended.

Polydipsia = Increased thirst.

Polyuria = Increased micturition (urination).

Pyometra = Accumulation of pus in the uterus; a serious condition in which ovariohysterectomy is usually the treatment of choice in addition to fluid therapy.

Pyrexia = Abnormally high body temperature; fever.

Respiratory Acidosis = Pulmonary retention of carbon dioxide.

Respiratory Alkalosis = Excessive loss of carbon dioxide.

Shock = Severe illness or trauma with a sudden fall in blood pressure (hypotension) leading to lack of oxygen in the body tissues.

Specific Gravity = The density of fluid compared with that of an equal volume of water.

Tachycardia = Abnormal increase in heart rate.

Tachypnoea = Abnormal increase in respiratory rate.

Thrombophlebitis = Formation of a blood clot associated with the inflammation of the lining of a vein.

Transcellular Fluid = A small percentage of extracellular fluid with a specialised function produced by active secretory mechanisms.

Uticaria = A skin condition caused by an allergy.

Vasconstriction = The contraction of a blood vessel wall; this causes decreased blood flow and a subsequent rise in blood pressure.