The Immune System Chapter 43 ~

PCA: List the organs involved in the immune sytem:

Lines of Defense Nonspecific Defense Mechanisms……

Innate Immunity First defense –Skin –Mucous membranes –Secretions- skin and mucous membranes

“You men come with me, the rest of you run with mucus…” Mucous membranes –Line digestive, respiratory and genital tracts –Low pH –lysozymes

Innate Immunity: Specialized phagocytic white blood cells Antimicrobial proteins Inflammatory response

Innate Immunity: 5 types of Leukocytes Neutrophils 60-70% WBCs; engulf and destroy microbes at infected tissue Short lived Monocytes 5% WBCs; develop into…. –Macrophages 1)phagocytosis –2)lysosomal enzymes destroy microbes Dendritic cells: Stimulate development of the acquired immune system

Innate Immunity: 5 types of Leukocytes Eosinophils 1.5% WBCs; destroy large parasitic invaders Enzymatic action- no phagocytosis Natural killer (NK) cells destroy virus-infected body cells & abnormal cells apoptosis

Antimicrobial Proteins: 1.Complement system- group of 30 proteins  Once activated can cause invading cells to lyse – burst –Compliment the ability of antibodies and phagocytes 2.Interferons (α, β and γ)  Immune response to viruses  Activates macrophages

The Inflammatory Response Tissue injury; release of chemical signals~ histamine (basophils/mast cells): prostaglandins: increases blood flow & vessel permeability

Dilation and increased permeability of capillary~ chemokines: secreted by blood vessel endothelial cells mediates phagocytotic migration of WBCs

Lymphatic System: Consists of: –Lymphatic vessels –Lymph nodes –Adenoids –Tonsils –Appendix –Spleen –Peyer’s patches

Lymphatic System: Function: –Traps foreign molecules and various substances –Returns lost fluids back to circulatory system

Lymphatic System: Connection with Immune System: –Foreign molecules and invaders encounter macrophages, dendritic cells, and lymphocytes which take various defense actions to activate and immune response and destroy pathogens.