Immune System Anatomy Joke of the Day Immune Systems Nonspecific immune system Immune Systems Nonspecific immune system Specific immune system Superficial Nonspecific Defenses Skin Superficial Nonspecific Defenses Skin Mucous membranes Internal Nonspecific Defenses Phagocytes Macrophages in interstitial fluid unattached and attached to reticular tissue in lymph system originated as monocytes increase number of vaccules containing lysozymes Neutrophils WBC become phagosytic when encountering pathogens evolved to destroy Eosinophils Internal Nonspecific Defenses Phagocytes Macrophages Neutrophils Eosinophils Mast cells bind to ingest and kill bacteria only slightly phagocytic Internal Nonspecific Defenses Phagocytes Macrophages Neutrophils Eosinophils Mast cells Natural killer cells NK cells lyse break apart and kill cancer or viral infected body cells type of lymphocyte not phagocytic Internal Nonspecific Defenses Phagocytes Macrophages Neutrophils Eosinophils Mast cells Natural killer cells Inflammation redness heat swelling and pain the idea of inflammation is to prevent the spread of a pathogen disposes of cellular debris and sets up the process of cellular repair Internal Nonspecific Defenses Phagocytes Macrophages Neutrophils Eosinophils Mast cells Natural killer cells Inflammation Antimicrobial proteins attack microorganisms or prevent their ability to produce Interferon protein secreted by infected cell that functions to save adjacent cells Complement system 20 or more proteins that are inactive and circulating in blood that get activated in inflammation Internal Nonspecific Defenses Phagocytes Macrophages Neutrophils Eosinophils Mast cells Natural killer cells Inflammation Antimicrobial proteins Interferon Complement system Fever increase in body temp systematic response to infection any body temp in the excess of 98 2 low grade are not big deal but high fevers are Phagocytic Mechanism Phagocyte recognizes pathogen s carbohydrate surface markers Enhanced via opsonization Cytoplasmic extensions adhere to pathogen adherence Pathogen pulled inside cell in vacuole Called phagosome Lysosome binds with phagosome forming phagolysosome Lysosomal enzymes digest pathogen Can be aided by respiratory burst Residual body formed and then expelled Natural Killer Mechanism NK cells detect infected or cancerous cells through lack of self markers or presence of certain sugars NK cells release perforins cytolytic Channels appear in target cells and nucleus disintegrates Inflammatory Mechanism Toll like receptors on macrophages recognize pathogens TLRs toll like receptors release cytokines mechanism to attract WBCs and promote inflammation response Other cells release other inflammatory mediator chemicals i e histamine prostaglandin Vessels in injured area dilate and increase permeability Hyperemia excess fluid accumulation in the area full of clotting factors and antibodies occurs Exudate accumulates causing edema swelling effective because it dilutes harmful substances brings in oxygen and nutrients brings in clotting proteins Results of Inflammation Injured cells release leukocytosis inducing factors Causes neutrophil release by red bone marrow Results of Inflammation Loss of fluids slows blood flow locally Results of Inflammation Inflammation causes production of selectins form of adhesion molecule on endothelial cells Margination occurs binding of selectin to neutrophil Neutrophils escape capillaries through diapedesis Results of Inflammation Inflammatory chemicals act as chemotactic agents attract cells to area Monocytes follow neutrophils Monocytes become macrophages after leaving capillaries Interferon Mechanism Cells infected by virus release interferons IFNs diffuse to nearby cells PKR protein synthesis is PKR interferes with viral stimulated replication IFNs also activate macrophages and NK cells Complement System Mechanism I Antibodies bind to pathogens Complement proteins bind to antibody complement fixation pathogen complexes Lysis phagocytosis and inflammation result Complement System Mechanism II Complement proteins bind to polysaccharide molecules on pathogens no antibodies involved Lysis phagocytosis and inflammation result Anatomy Joke of the Day Fever Mechanism Leukocytes and macrophages exposed to pathogens secrete pyrogens Pyrogens cause hypothalamus to raise body temp increase reduced iron and zinc availability iron and zinc are both needed by bacteria for replication 2 ways to increas body temp is shivering thermogenesis and non shivering thermogenesis but for viral infection excess zinc helps Antigen French Anatomy Joke of the Day Antigenic Properties Immunogenicity stimulates increase in specific lymphocytes and antibodies cells of specific immune system Reactivity cells that have antigens have ability to react with activated specific lymphocytes and antibodies Antigenic determinants cells that have antigens on their surfaces determine antigenic determinants part of antigen that is immunogenic first term above Major Histocompatibility Complex Self antigens Characteristics of Specific Immunity Pathogen specific not everything attacks it Not immediately active time lag Systemic is not just occurring at site of infection occurs all over the body Provides memory memory cells that allow us to act faster next time we encounter that pathogen Pathways Humoral antibody mediated pathway from fluids antigenic determinants of the foreign cells causes production of antibodies by lymphocytes indirect and circulate in blood lymph once antibodies are produced they will bind to any free floating pathogen once they attach they have marked the pathogen for destruction and they are destroyed through phagocytosis and complement system Pathways Humoral Cell mediated lymphocytes act directly on pathogen by lysing it or indirectly by releasing mediators that cause it to be destroyed targets are different between this and humoral interacts with cell targets cancerous or cells with infected MHC Lymphocyte Production Produced by stem cells in red bone marrow Lymphocyte Production Produced by stem cells in red bone marrow T cells become immunocompetent in thymus Lymphocyte Production Produced by stem cells in red bone marrow T cells become immunocompetent in thymus B cells become immunocompetent in bone marrow Lymphocyte Production Produced by stem cells in red bone marrow T cells become immunocompetent in thymus B cells become immunocompetent in bone marrow Immunocompetent cells mature in