A PII Exam 3 Objectives Power Point 1 The Immune System Objective 1 Define the immune system and its 3 lines of defense Functional system made up of two intrinsic defense systems that act independently and cooperatively to provide resistance to disease Innate nonspecific Defense System 1st and 2nd Lines of defense respond within minutes 1st External Membranes Skin Mucosa Adaptive specific Defense System 3rd Line of defense 2nd Takes effect when 1st has been penetrated inflammation proteins phagocytes Objective 2 Explain how the innate and adaptive systems are intertwined Adaptive specific Defense System 3rd Line of defense Attacks foreign substances This system takes longer than the innate to work Innate and adaptive systems are intertwined Proteins released during an innate response alerts cells of the adaptive system about the presence of a foreign substance Essentially the innate system sets the adaptive system up to be effective Objective 3 What are surface barriers and how do they function as the first line of defense Skin mucous membranes and their secretions are the body s 1st line of defense Keratin keratinization hardening in the skin provides a tough barrier as the first line Mucous membranes provide the lining for all body cavities that open to the exterior Serve as physical barriers And also secrete protective chemicals Skin keratinized epithelial membrane Resistant to most weak acids bases toxins Mucous membranes Protective chemicals secreted 1 acidity of skin secretions pH 3 5 inhibits bacterial growth 2 stomach mucosa secretes HCl and protein digesting enzymes to kill microorganisms 3 saliva and lacrimal fluid contain lysozymes enzyme to destroy bacteria 4 mucus to traps microorganisms trying to enter these openings Objective 4 Explain Nonspecific Cellular Chemical Defense the second line of defense including phagocytes phagocytosis phagocyte mobilization and other factors in this line Little cut can enable and elicit internal innate 2nd Line Killing Pathogens and Repair Tissue Phagocytes 2 types confront pathogens Macrophages Leave the bloodstream in search of foreign substances Neutrophils Type of white blood cell that becomes phagocytic upon and encounter Both derive from white blood cells Natural Killer Cells NK cells Inflammatory Response Antimicrobial Proteins Complement Proteins Interferons Fever Adherence is made possible by recognizing the pathogen Complementary proteins help with this Vaccine Methods of Pathogen Destruction simple digestion by lysosomal enzymes respiratory burst free radicals which kill cells K enters phagosome pH rises activates protein digesting enzymes that digest the invader Defensins are chemicals produced by neutrophils that pierce the pathogen membrane Natural Killer Cells non phagocytic Located in blood and lymph Defensive cells that can kill infected cells before the adaptive immune system is activated Including cancer cells They eliminate cells through direct contact by 1 Determining the lack of cell surface receptors 2 Determining certain cell surface sugars Secrete chemicals that enhance the inflammatory response Stimulate apoptosis of target infected cell cell death Objective 5 Describe the responses to injury reactive hyperemia and the mechanisms of occlusion training Inflammatory response is triggered when body tissues are injured 1 Prevents the spread of damaging agents to nearby tissues 2 Disposes of cell debris and pathogens 3 Sets the stage for repair Four cardinal signs redness heat swelling and pain may hinder joint movement impairment of function 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 the injured area more blood flow hyperemia accounts for redness and heat Chemicals also increase permeability of capillaries exudates accumulate fluid w clotting factors and antibodies which causes swelling pressure on nerves causes pain surge of fluids helps to dilute harmful substances and delivers important proteins to site Upon injury fibrin mesh Occlusion Results in reactive hyperemia mediated vasodilation Mechanisms are 1 Fiber Type recruitment 2 Accumulation of metabolites lactate GH 3 mTOR activation protein synthesis pathway Objective 6 Describe Antimicrobial Proteins Enhance the Innate defenses by attacking microorganisms not allowing reproduction Stimulate production of proteins that will interfere with viral replication in healthy cells Interferons Secreted by virus infected cells Complement Complement System Inactive Proteins in blood Cascade of activation of proteins activated by injury This activation releases chemicals which amplify inflammation through vasodilatory release Classical and Alternative Pathways of activation Viruses damage the body by invading tissue cells and taking over the cellular metabolic machinery to reproduce themselves Interferons are small proteins secreted by virus infected cells that help protect cells that have not yet been infected diffuse to nearby cells stimulate synthesis of proteins that interfere with viral replication in healthy cells block protein synthesis and degrade viral RNA Objective 7 Describe two biochemical pathways activate the complement system Complement refers to a group of at least 20 plasma proteins that normally circulate in the blood in an inactive state Group includes C1 C9 factors B D and P plus several regulatory proteins Amplifies the inflammatory process causes cell lysis of certain bacteria and other cell types Enhances complements the effectiveness of both innate and adaptive defenses The classical pathway involves the binding of antibodies produced by adaptive immune system to the invading organisms and the subsequent binding of C1 to the antigen antibody complexes complement fixation The alternative pathway factors B D and P interact with polysaccharide molecules on the surface of certain microorganisms The two converge on C3 cleaving it into C3a and C3b C3b will bind to the target cell s surface and trigger the insertion of MAC which will form and stabilize a hole in the membrane causing lysis via an influx of water C3b will also coat the microorganism opsonization allowing neutrophils and macrophages to engulf and destroy more rapidly C3a will amplify the inflammatory response C reactive protein is produced by the liver and is used as a clinical marker to assess acute infection of
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