A complex system of various types of cells that protects the body against disease producing organisms and other foreign invaders.
The immune system is made up of organs (e.g. lymph glands), specialised cells (white blood cells) and signalling molecules (e.g. antibodies). The immune system protects us from disease by recognising and neutralising any foreign matter in the body. It will:
destroy bacteria and viruses
neutralise toxins
repair damage to cells following injury
destroy the body's own cells if they are no longer functioning properly e.g. to prevent cancer
