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Unformatted text preview: LS 2 Review: Immune System Ch.18 1. Immunology- study of physiological defenses/ recognize self from nonself 2. Microbes : Want to infect b/c unlimited source of nutrients. 1) Bacteria: unicellular organisms that have a cell wall, plasma membrane, no membrane-bound organelles, harmful toxins. 2) Viruses: Made of nucleic acid surrounded by a protein coat (Caspid); Do not have protein machinery; Invade and take over host cells machinery; Insert its DNA; Replicate in host until cell cant contain; Not considered living until in body. 3. Immune System- 1) Protects against infection and microbes 2) Isolates or remove nonmicrobial foreign substances 3) Destroy Cancer Cells i. Nonspecific Immune Defenses: Protect against foreign substances without having to recognize their identity. ii. Specific Immune Defenses: Depends upon specific recognition. 4) Physical barriers and Chemical Barriers: i. First Line: skin glands, salivary glands, tonsils and lacrimal glands (tears/ eye) ii. Secretion of lysozymes and lactoferrin (holds onto Iron to prevent bacteria reproduction. iii. Mucus- antimicrobial enzymes, sticky to prevent bacteria from entering blood. Bacteria brushed to pharynx and down esophagus to be killed by acid in stomach. iv. Cough and Sneeze Reflex 4. Cells of the Immune System: 1. Leukocytes, 2. Plasma Cells, 3. Macrophages, 4. Mast Cells 1) Leukocytes: (most abundant and diverse) i. Neutrophils: Perform Phagocytosis and Release Vasodialators and Chemotaxins (attract other immune cells to site of infection). ii. Basophils : release molecules that aid in the inflammatory process. iii. Eosinophils : Cytotoxic, less common. iv. Monocytes: Immature form of macrophages, become a macrophage when they enter tissue. Macrophages: (fn. In non-specific and specific) a. Found in various epithelia in contact with external environment....
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- Spring '09