Post on 02-Jan-2016
Nonspecific Defenses Physical barriers Skin Creates effective barrier
Multiple layers Keratin Desmosomes
Nonspecific Defenses Physical barriers Secretions Oil, sweat, mucus Wash away pathogens
Lysozyme kills bacteria
Nonspecific Defenses Phagocytes Eosinophils Target foreign compounds or pathogens coated with antibodies
Nonspecific Defenses Phagocytes NK cells Natural killer cells
Large lymphocytes Destroy abnormal cells
Constantly monitor normal tissues
Nonspecific Defenses Inflammatory response Histamine released by basophils Blood vessels dilate Increased blood flow to damaged area Phagocytes mobilized Complement activated
20 proteins React in chain reaction Attacks & breaks down cell walls
Specific Defenses Target specific antigen Involves lymphocytes Remembers antigens encountered in the past
Ignores self and attacks nonself
Specific Defenses Cell-Mediated Immunity Provides defense against abnormal cells & pathogens inside living cells
Involves T cells (green cell)
Specific Defenses Cell-Mediated Immunity Antigen engulfed by macrophage
Antigen broken down Macrophage presents pieces of antigen on cell membrane
Specific T cell binds to antigen pieces
Specific T cell activated
Specific Defenses Cell-Mediated Immunity Activated T cell divides & differentiates Helper T cells – stimulate immune response
Cytotoxic T cells – killer T cells Memory T cells – remember encountered antigens; activated with 2nd exposure
Supressor T cells – slows things down
Specific Defenses Antibody-Mediated Immunity Provides defense against antigens & pathogens in body fluids
Involves B cells
Specific Defenses Antibody-Mediated Immunity Specific B cell activated Activated B cell divides & differentiates Plasma cells
Produce antibodies Memory B cells
Remember encountered antigens Activated with 2nd exposure
Specific Defenses Antibody-Mediated Immunity Specific B cell activated Activated B cell divides & differentiates Plasma cells
Produce antibodies Memory B cells
Remember encountered antigens Activated with 2nd exposure
Specific Defenses Primary Immune Response Period I B cell activated Activated B cell divides & differentiates
Plasma cells produce antibodies