Immune system Chp. 16 (pp. 323-350)

~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!!!!!!!!!