A P Exam 3 Objectives Power Point 1 The Immune System 1 Define the immune system and its 3 lines of defense 2 intrinsic defense systems that act independently and cooperatively to provide resistance to defense 1st line of defense surface barriers external membranes skin mucous membranes and their secretions responds within minutes innate nonspecific defense system 2nd line of defense inflammation phagocytes and proteins takes effect when 1st has been penetrated innate nonspecific defense system 3rd line of defense attacks foreign substances takes longer to work adaptive specific defense system 2 Explain how the innate and adaptive systems are intertwined proteins released during innate defense system alert cells of adaptive defense system about presence of foreign substances o innate sets up adaptive to be effective 3 What are surface barriers and how do they function as the first line of defense skin mucous membranes and their secretions keratin keratinization hardening in skin provides tough barrier as 1st line of defense mucous membranes provide lining for all body cavities that open to exterior physical barriers o secrete protective chemicals acidity of skin chemicals pH 3 5 which inhibits bacterial growth stomach mucosa secretes HCl and protein digesting enzymes to kill microorganisms saliva and lacrimal fluid contain lysozymes which destroy bacteria mucus to trap microorganisms trying to enter openings in body skin keratinized epithelial membrane that is resistant to most weak bases acids and toxins 4 Explain Nonspecific Cellular Chemical Defense the second line of defense including phagocytes phagocytosis phagocyte mobilization and other factors in this line 2nd line of defense kill pathogens and repair tissue phagocytes confront pathogens derived from white blood cells o neutrophils white blood cell that becomes phagocytic upon an encounter o macrophages leaves the blood stream in search of foreign substances Phagocytosis 1 phagocyte adheres to microbe and pathogen debris adherence made possible by recognizing pathogen vaccines complementary protein helps with this 2 plasmic extensions bind to particle and pull it inside membrane lined vacuole phagosome phagolysosome 3 phagosome fuses with lysosome which has strong digestive enzymes to form 4 microbe is killed and digested by lysosomal enzymes leaving residual body simple digestion by lysosomal enzymes respiratory burst free radicals which kills cells K enters phagosome pH rises activates protein digesting enzymes to digest invader defensins chemicals produced by neutrophils that pierce pathogen membrane 5 residual body removed by exocytosis Phagocyte mobilization phagocytes flooding injured area after inflammation 4 steps 1 leukocytosis damaged cells induce release of neutrophils from red bone marrow to increase WBCs in blood 2 margination clinging of phagocytes to inner calls of capillaries inflamed cells sprout CAMs and neutrophils adhere to these CAMs on inner walls of capillaries 3 diapedesis chemical signaling allows neutrophils to squeeze through capillary walls 4 chemotaxis inflammatory chemicals which act as magnets chemotactic to draw in phagocytes Natural Killer cells non phagocytic o in blood and lymph o kill infected cells before adaptive immune system is activated o eliminates cells through direct contact by determining lack of cell surface receptors as well as determining cell surface sugars o chemicals secreted enhance inflammatory response o stimulate apoptosis of target infected cell cell death Inflammatory response triggered when body tissues are injured o prevents spread of damaging agents to nearby tissues o disposes of cell debris and pathogens o sets stage for repair Antimicrobial proteins enhance innate defense by attacking microorganisms and not allowing reproduction o Complement proteins inactive proteins in blood cascade of activation proteins activated by injury releases chemicals that amplify inflammation through vasodilatory release o Interferons secreted by virus infected cells stimulate production of proteins that will interfere with viral replication in healthy cells Fever systemic response to invading microorganisms o regulated by neurons in hypothalamus changes in response to pyrogens fever producing substance o mild to moderate fever is beneficial because the liver retains iron and zinc and it increases metabolic rate of tissue cells speeds up repair o high fever is dangerous because enzymes get denatured 5 Describe the responses to injury reactive hyperemia and the mechanisms of occlusion training inflammatory responses triggered when body tissues are injured o 4 cardinal signs redness heat swelling pain upon injury o release of chemical mediators such as cytokines promote inflammation and attract WBCs histamine by mast cells kinins prostaglandins leukotrienes and complement will induce vasodilation of small blood vessels in injured area hyperemia more blood flow redness heat coming from injured area o chemicals also increase permeability of capillaries exudates highly concentrated antibodies accumulate which cause swelling pressure on nerves causes pain surge of fluids helps dilute harmful substances and brings important proteins fibrin mesh created occlusion training results in hyperemia mediated vasodilation o fiber type recruitment o accumulation of metabolites lactate GH o mTOR activation protein synthesis pathway 6 Describe Antimicrobial Proteins enhance innate defense by attacking microorganisms and not allowing reproduction o Complement proteins inactive proteins in blood cascade of activation proteins activated by injury releases chemicals that amplify inflammation through vasodilatory release group of 20 plasma proteins that normally circulate in blood in inactive state C1 C9 factors B D regulatory proteins amplifies inflammatory process causes cell lysis of certain bacteria and other cell types enhances effectiveness of both innate and adaptive defense systems o Interferons secreted by virus infected cells stimulate production of proteins that will interfere with viral replication in healthy cells gamma interferon lymphocytes enhances T cell activity alpha interferon most leukocytes except lymphocytes reduce inflammation beta interferon fibroblasts reduce inflammation IFN alpha used to treat genital warts and some success with hepatitis C IFN beta used to treat MS de myelinating disease IFN gamma treats chronic granulomatous disease abnormal WBCs 7 Describe two biochemical
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