THE IMMUNE SYSTEM

The immune system defends the body against infection and other dangerous agents

Non-Specific Immunity

●   protects against all threats
●   physical barriers eg. skin, mucus membranes, nasal hairs
●   chemical barriers eg. saliva, tears, stomach acid, acidic environment of genital tract

Cellular Immunity

●   attack of microbes by specialised cells
●   inflammation - swelling of area of infection by cells and release of fluids -> isolates disease agents
●   phagocytes (white blood cells) - engulf (eat) disease agents - collection of dead phagocytes form pus

Specific Immunity

●   production of specific proteins against disease agents (antibodies) which disable or destroy the microbes
●   antibodies produced by lymphocytes in the lymph glands, thymus, bone marrow and spleen
●   antibodies are made in response to other protein molecules (antigens) found on the surface of foreign agents

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