HHP 3500 Lecture 32: Innate Immune System
27 Oct 2016
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Document Summary
Responses triggered due to foreign item (non-specific) First line of defense against microbes are barriers offered by body surfaces exposed to external environment: epithelial tissue, cough and sneeze reflexes, secretions (tears, saliva, mucus) Non specific- response: inflammation-local response to injury or infection. Brings immune system to site of infection. Increase activity of white blood cells in that local area. Phagocytosis-englufing and destroying foreign matter: primary-neutrophils and macrophages, phagocytosis enhanced via opsonins (flags, secrete cytokines and antimicrobial agents. Protein c3 leads to deposition of c3b protein on microbe surface. Acts of opsonin which makes it easier for phagocytosis to find it. It also leads to production and insertion of membrane attack complex (hole in membrane, where extracellular fluid can flow into microbe and make it explode!) Tissue repair-final step: secretes collagen by fibroblast into local area, which forms scar tissue, stimulates new blood vessel growth, may involve mitosis of tissue cells, interferons.
