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Unformatted text preview: 4-1-2008CHAPTER 32: DEFENSE AGAINST DESEASE: THE IMMUNE SYSTEMThree lines of defense against microbial attack:-Non Specific External barriers1.Skin, Mucous Membranes(Ex. Castle)Non specific because it keeps EVERYTHING out-Nonspecific Internal Membranes1.Phagocytic and natural killer cells, Inflammation, Fever-Specific Immune Response1.Uses antibodies and antibody-like receptors2.Cell mediated immunity, and Humeral immunity 1.EXTERNAL BARRIERS(skin, mucous membranes)keep everything out (dirt, dust, microbes, etc.)a.Skin1.Physical barrier to microbial entry2.Puncture, or cut, is a way to get infection. 3.Inhospitable environment for growth; dry, dead cells at surface. Sweat/sebaceous glands secreting acids and natural antibiotics like lactic acidb.Mucous Membranesof respiratory and digestive tracts well-defined. Secretions have antibacterial enzymes. c.Stomach; if microbes swallowed, acids and protein-digesting enzymes destroy them. 2.NONSPECIFIC INTERNAL DEFENSEa.PHAGOCYTIC CELLS; white blood cells (WBC) in extracellular fluid, amoeboid shape, destroy microbes by phagocytosis. b.NATURAL KILLER CELLS: WBC that destroy body cells infected by viruses and cancerous cells by punching HOLES in them. c.INFLAMMATORY RESPONSE, cause by large scale microbial invasion through wound1.histamine released by damaged cells1.histamine increases blood flow, makes one bleed, blood is sterile, like it washes out wound. 2.This wash out leads to inflammation (red, swollen, warm)3.Other chemicalsmacrophages (WBC engulf bacteria, dirt, and tissue debris)4.Blood clotting walls off wounded area. Pus is just WBC dying. -Textbook Picture1.Tissue damage carries bacteria into wound2.Wounded cells release chemicals that stimulate mast cells3.Mast cells release histamine4.Histamine increases capillary blood flow and permeability5.Phagocytes leave capillaries and ingest bacteria and dead cells d.FEVERresponse to microbes establishing a major infection. Low grade (100-102 F) response to microbes establishing a major infection....
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