Adipose tissue = Fibrous tissue containing many fat cells.

Afferent = Conveying towards the centre; afferent nerves are sensory nerve fibres that conduct impulses from the periphery towards the vein.

Anatomy = The science of the structure of the body.

Anion = A negatively charged ion.

Bowman's capsule = The expanded end of the kidney tubule which surrounds the glomerulus.

Buffer cells = Cells that oppose changes.

Cartilage = A specialised fibrous connective tissue.

Cation = An ion with a positive charge.

Caudal = Towards the tail.

Centriole = two cylindrical structures located in the cell cytoplasm near to the nucleus and Golgi apparatus. They are associated with cell reproduction.

Centrosome = The part of the cytoplasm containing the centrioles.

Chromosome = A structure within the nucleus of a cell containing DNA which transmits genetic information.

Cilia = Microscopic filaments projecting from some epithelial cells.

Connective tissue = Tissues that develop from the mesenchyme and are formed of a matrix containing fibres and cells.

Cranial = Towards the head.

Cytoplasm = The protoplasmic part of the cell surrounding the nucleus; the substance of the cell other than the nucleus.

Dorsal = Towards the back.

Dorsal plane = A horizontal plane parallel to the dorsum.

Efferent = Conveying from the centre; efferent nerves are the motor nerves coming from the brain to supply the muscles and glands.

Electrolyte = A compound which when dissolved in a solution will disassociate into ions.

Electron microscope = A type of microscope employing a beam of electrons which allows very small particles such as viruses to be examined.

Endocrine = Secreting within; applied to glands whose secretions (hormones) flow directly into the blood and not outwards through a duct.

Endoplasmic reticulum = Folded membranous structures within a cell situated close to the nucleus. Rough ER holds ribosomes and synthesises proteins, whilst smooth ER produces lipid secretions.

Enzyme = A protein which will catalyse a biological reaction.

Eukaryote = A cell possessing a membrane bound nucleus.

Exocrine = Pertaining to those glands which discharge their secretion by means of a duct.

Extrinsic = Originating externally. Extrinsic muscles originate away from the part which they control.

Fibroblast = An immature fibrous connective tissue cell that can produce collagen fibres.

Fibrocyte = A mature fibrous connective tissue cell that is relatively inactive.

Golgi apparatus = Specialised cell structures seen near to the nucleus; consists of a series of tubes that store lysosomal enzymes.

Haemopoeisis = The formation of red blood cells.

Haversian system = The series of canals within bone that carry blood vessels, nerves and lymphatics.

Histamine = An enzyme released by the body tissues in response to an allergy.

Histiocyte = A stationary macrophage of connective tissue. It is derived from the reticuloendothelial cells and acts as a scavenger, removing bacteria from the blood and tissues.

Histology = Anatomy seen under the microscope.

Histopathology = The diseased state of the body seen microscopically.

Hypertonic = Exerting an osmotic pressure greater than that of the body fluids.

Hypotonic = Exerting an osmotic pressure lower than that of the body fluids.

Interstitial fluid = Tissue fluid; the fluid that bathes the cells of the body outside of the blood.

Intrinsic = Particular to or contained within an organ.

Invertebrate = An animal without a backbone.

Ion = An atom or group of atoms having an electric charge.

Isotonic = Exerting an osmotic pressure equal to that of the body fluids.

Keratin = An albuminoid substance which forms the principal constituent of all horny tissue.

Lacunae = Depressions or pits.

Lamellae = Thin layers or sheets.

Ligament = A band of fibrous tissue connecting bones forming a joint.

Lymph = The fluid from the blood which has transuded through the capillary walls in order to supply nutrients to the tissue cells.

Lysis = Cell death.

Lysosome = A particle found in the cell cytoplasm which causes the breakdown of metabolic substances and foreign particles within the cell.

Macrophage = A large reticuloendothelial cell which has the power to ingest cell debris and bacteria; present in connective tissue especially when there is inflammation.

Mast cell = A histamine releasing cell that facilitates allergic reactions.

Median plane = The plane that divides the body longitudinally into two equal halves.

Mediastinum = The space between the left and right pleural sacks.

Metabolism = The sum of the physical and chemical processes by which living organised substance is built up and maintained (anabolism), and by which large molecules are broken down into smaller molecules to make energy available to the organism (catabolism).

Mitochondria = Bodies contained within the cytoplasm of cells concerned with energy production and the oxidation of food.

Monocyte = A white blood cell having one nucleus, derived from the reticular cells, and having a phagocytic action.

Myelin = A fat-like substance covering nerve fibrils for insulation.

Nephron = The functional unit of the kidney, comprising Bowman's capsule, the proximal and distal tubules, the loop of Henle and the collecting duct which conveys urine to the renal pelvis.

Neurilemma = The sheath of connective tissue that surrounds the axon of a nerve cell.

Neuroglia = The connective tissue that runs between neurons.

Neuron = A nerve cell.

Nucleolus = A spherical structure found within the nucleus of the cell; responsible for the manufacture of ribosomes.

Nucleus = The essential part of the cell which governs nutrition and reproduction.

Organelle = Microscopic structures within a cell which are not part of the nucleus.

Osmosis = The passage of fluid from a low concentration solution to a higher concentration solution via a semi-permeable membrane.

Osmotic pressure = The pressure by which water is drawn into a solution through a semi-permeable membrane.

Pathology = The diseased state of the body as seen with the naked eye.

Perichondrium = The membrane covering cartilaginous surfaces.

Peritoneum = The serous membrane lining the abdomen and most of the pelvis.

Phagocyte = A blood cell able to ingest bacteria, protozoa and foreign bodies in the blood.

Phagocytosis = The ingestion by a cell of solid substances.

Pinocytosis = The ingestion by a cell of liquid substances.

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

Pleura = The serous membrane lining the thorax.

Physiology = The science of the functioning of living organisms.

Protoplasm = The essential chemical compound of which living cells are made; the material which makes up cytoplasm.

Pyrexia = Fever.

Ribosomes = RNA and protein containing particles within a cell.

Rostral = Towards the nose.

Sagittal plane = Any plane lying parallel to the median plane (which divides the body longitudinally into two equal halves).

Serum = Plasma from which the clotting agents have been removed.

Sesamoid bone = A bone within a tendon; EG the patella.

Solution = A liquid in which one or more substances have been dissolved.

Solvent = A liquid which has the power to dissolve.

Sudiferous glands = The sweat glands.

Tendon = A band of fibrous tissue attaching muscle to a bone.

Tissue = A group or layer of similarly specialised cells that together perform certain special functions

Transverse plane = A plane running perpendicular to the long axis of the part of the body to be sectioned.

Vacuole = Fluid filled cavity within the cell cytoplasm left following digestion.

Ventral = Towards the chest.

Vertebrate = An animal with a backbone.

Viscera = Organs located in any of the body cavities.