Abdomen: Lower part of the trunk (central part of the body) between the thorax (chest) and the hips.
Absorption: Process by which the products of digestion pass through the wall of the small intestine into the bloodstream.
Accommodation: Adjustment made by changing the shape of the lens of the eye so it can focus on near or distant objects.
Acne: Skin disorder causing spots that result from inflamed sebaceous glands and hair follicles.
Adolescence: Transition period between childhood and adulthood that occurs during the teenage years.
Aerobic respiration: Release of energy from glucose that takes place inside cells and requires oxygen.
Alimentary canal: Hollow tube which extends from the mouth to the anus, and includes the pharynx, oesophagus, stomach, and small and large intestines.
Allergy: Illness caused by overreaction of the body’s immune system to a normally harmless substance.
Alveoli (sing. Alveolus): Microscopic air bags inside the lungs through which oxygen enters, and carbon dioxide leaves, the bloodstream.
Amino Acid: One of a group of 20 chemical compounds that are the basic building blocks from which proteins are made.
Amputation: Surgical removal of all or part of an arm or leg.
Anaerobic respiration: Release of the energy from glucose that takes place inside cells and does not use oxygen.
Anaestheticts: Drug used to temporarily abolish feelings of pain in a patient during surgery or while giving birth.
Anatomy: Study of the structure of the body, and how its parts relate to one another.
Angiogram: Special type X-ray that reveals the outline of blood vessels after a dye that absorbs X-rays has been injected into them.
Antibody: Substance released by lymphocytes of the immune system that disables a pathogen and marks it for destruction.
Antigen: Foreign substance, usually found on the surface of pathogens such as bacteria, that triggers the immune system to respond.
Antiseptic: Chemical applied to the skin to destroy bacteria and other micro-organisms before they can cause infectious.
Apgar Score: System of scoring used to assess the condition of a newborn baby.
Appendicular skeleton: Part of the skeleton made up of the bone of the pectoral and pelvic girdles, and those of the upper and lower limbs.
