PET 3323 Spring 2012 Study Guide Exam 3 immune System chapter 22 begin on page 886 Integumentary System chapter 5 pages 153 160 164 165 167 169 175 177 Energy Balance and Thermoregulation chapter 25 pages 1048 1052 Urinary System chapter 26 pages 1065 1092 1096 1099 Immune System made up of 2 intrinsic defense systems that act independently and cooperatively to provide resistance to disease innate and adaptive 1 Know the major components of the immune system e g 1st 2nd and 3rd lines of defense components of each and their roles in immunity 1st line of defense external body membranes intact skin and mucosae innate nonspecific surface barriers o Skin o Mucous membranes Keratin is resistant to most weak acids and bases and to bacterial enzymes and toxins Keratinized epithelial membrane Traps foreign substances Mucous membranes line all body cavities that open to the exterior digestive respiratory urinary and reproductive tracts Skin secretions are acidic pH 3 5 which inhibit bacterial growth ie vaginal secretions stomach mucosa secretes HCl and protein digesting enzymes Sebum contains chemicals that are toxic to bacteria Saliva and tears contain lysozyme destroys bacteria Sticky mucous traps microorganisms mucous coated hairs too Vaginal secretions are low pH 2nd line of defense antimicrobial proteins phagocytes and other cells to inhibit the invaders spread throughout the body innate nonspecific internal defenses o Phagocytes macrophages and neutrophils o Natural Killer Cells NKs Macrophages main type of phagocyte big eaters Derive from WBC s called monocytes macrophages in tissue Neutrophils most abundant WBC Become phagocytic when encountering infectious material in tissues Eosinophil phagocyte WBC weak phagocyte defense against parasitic worms police blood and lymph Lyse and kill cancer cells induce target cells to undergo apoptosis Part of large granular lymphocytes Nonspecific detect the lack of self cell surface receptors and recognize certain surface sugars on target cells Also secrete chemicals that enhance inflammatory response Inflammatory response o o Antimicrobial proteins complement proteins and interferon s o Fever elevated body temp systematic response to invading microorganisms Body thermostat reset upward by pyrogens secreted by leukocytes and macrophages exposed to bacteria and other microbes Elevated temps intensify the effects of interferon s inhibits growth of some microbes and speeds up repair processes 3rd line of defense attacks particular foreign substances adaptive specific INNATE 1st and 2nd nonspecific skin barriers skin mucous membranes and Internal defenses phagocytes fever NK cells antimicrobial proteins inflammation ADAPTIVE 3rd line speficif humoral immunity B cells and cellular immunity T cells o Humoral immunity also called antibody mediated immunity Antibodies bind to bacteria and their toxins and free viruses B cells o Cellular immunity also called cell mediated immunity Lymphocytes attack virus or parasite infected tissue cells and cancer cells T cells 2 Understand the basic process of phagocytosis and phagocyte mobilization leukocytosis margination diapedesis chemotaxis Phagocytosis damage Adherence phagocyte attaches to microbe Ingestion engulf microbe digestion lysozyme enzymes break down microbe killing Chemotaxis phagocytes to Adherence is more probably when opsonization occurs Opsonization complement proteins or antibodies coat foreign particles it makes it tasty because the coating provides handles to which the phagocyte receptors can bind Phagocyte mobilization soon after inflammation begins the damaged area is invaded by more phagocytes neutrophils first then macrophages If the inflammation was provoked by pathogens complement a group of plasma proteins is activated and elements of adaptive immunity lymphocytes and antibodies also invade injured site Leukocytosis means increase in WBCs DeiaPEDesis think foot walking away After chemotaxis macrophages replace the neutrophils macrophages are final disposal of cell debris these are therefore apparent in chronic inflammation not acute o neutrophils short term macrophages long term Complement group of plasma proteins 3 Understand what triggers the inflammatory response and what causes each of the 4 cardinal signs of inflammation Inflammatory nonspecific defensive Inflammatory response whenever body tissues are injured by physical trauma intense heat irritating chemicals or infection by viruses fungi or bacteria the 4 cardinal signs of acute inflammation are shown in red boxes heat redness pain swelling as is limitation of joint movement which is some cases constitutes a fifth cardinal sign impairment of fxn Inflammatory Response Macrophages and certain skin membranous cells bear surface membrane receptors called TLR s TLR s triggers a release of chemicals called cytokines that promote inflammation and attract WBC s to the scene Mast cells release histamine histamine promotes vasodilation of arterioles increases permeability of capillaries and promotes exudates formation Injured and stressed tissue cells phagocytes lymphocytes basophils and blood proteins are all sources of inflammatory mediators too These include not only releasing histamine and cytokines but also kinins prostaglandins leukotrienes and complement These all have individual inflammatory roles BUT they all cause small blood vessels in the injured area to dilate As more blood flows into the area local hyperemia increased blood flow to area occurs cauing redness and heat 2 of the cardinal signs as capillaries become more permeable exudate fluid containing clotting factors and antibodies seeps from the blood into the tissue spaces causing local edema swelling another red cardinal This swelling presses on adjacent nerve endings contributing to a sensation of pain last cardinal Pain also results from the release of bacterial toxins and the sensitizing effects of released prostaglandins and kinins FYI edema is good bc it helps dilute harmful substances and it delivers important proteins such as complement and clotting factors to the interstitial fluid 4 Understand the stimulation and function of interferons and the complement system Antimicrobial Proteins attack microorganisms directly and or hinder their ability to reproduce 2 main kinds interferons and complement proteins Interferons infected cells can do little to save themselves once their infected BUT some can secrete small proteins called interferons IFN s to help protect
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