Immune system Chp. 16 (pp ) ~20,000 genes affect immunity, usually polygenic or multifactorial traits

Major Structures- Lymphocyte (produce by spleen) - one kind of white blood cell - T-cell and B-cell Lymph vessels Lymph nodes White blood cells Spleen Skin

Function of the system The immune system is the system of specialized cells and organs that protect an organism from outside biological influences Defends against pathogens and disease

–Cell surfaces used to recognize “foreign” or “nonself” surfaces initiate immune response –Autoimmune- immune system attacks individuals own tissues or organs –Genes encode for antibodies are proteins which attack foreign molecules cytokines are biochemicals which attack foreign molecules –antigens molecules that cause an immune response

Lymph nodes

Spleen -Store blood -Kill old RBC -Produce lymphocyte

AIDS HIV (human immunodeficiency virus) infection will lead to immune system collapse HIV usually invades helper T cell, which begin to produce HIV soon after infection. Helper T cell die, the –immune system gradually weakens –becomes overwhelmed by pathogens that would normally detect and destroy.

Diseases associated with that system Graves’ disease Multiple sclerosis Rheumatoid arthritis Systemic lupus erythematosus (SLE) - facial skin rash, painful joints, fever, fatigue, kidney problem, weight loss Type I diabetes

One interesting fact Allergy is the body’s overreaction to a normally harmless antigen Allergy- causing antigens include pollen, spores, foods, drugs, and dust mites. Allergies are caused by our immune system protecting us too much!!!!!!!!!