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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 cell’s machinery; Insert its DNA; Replicate in host until cell can’t 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