BIOS 2400 Lecture Notes - Lecture 15: Cell-Mediated Immunity, Phagolysosome, Mucous Membrane

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Bios 2400 - chapter 15 - immune system. 15. 1 defense mechanisms: functional system rather than organ system, hematopoietic, vasculature, lymphatic. Innate: structural defenses; responds to nonspecific foreign substances: first line: external surface epithelium and membranes; physical barrier, second line: inflammatory processes; antimicrobial proteins, phagocytes etc, adaptive: responds to specific foreign substances. Innate and adaptive mechanisms work together: b-cells: make anti-bodies and binds to antigens, t-cells: recognize specific antigens and induce different macrophages to get rid of different kinds of pathogen ex. cancer. Ingestion: formation of phagolysosomes: respiratory bursts: merge phagosome with lysosome and flood phagolysosome with free radicals (macrophage, defensins: proteins that crystallize out of solution and pierce pathogen membranes (neutrophils) Inflammatory response: signs are associated with vasodilation & increased vascular permeability: dilation: redness, heat (caused by histamine, permeability: edema, (increased pressure) pain, pain also associated with bacterial toxins & some mediators (kinins, pgs) Inflammatory response: mechanisms causing vasodilation and vascular permeability.