Final MCB Study Guide

Final MCB Study Guide - Chapter 15 - Defense Mechanisms I....

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Chapter 15 - Defense Mechanisms I. Nonspecific defense: barriers to penetration of body/ internal defenses. A. Phagocytic cells engulf invading pathogens. B. Interferon – polypeptide secreted by infected cell protect other cells II. Specific immune responses are directed against antigens. A. Antigens – large, complex, and foreign molecules B. Antigenic determinant sites stimulate production of diff. antibodies. III. Specific immunity = lymphocytes. A. B lymphocytes secrete antibodies and provide humoral immunity. B. T lymphocytes proved cell-mediated immunity. Functions of B Lymphocytes I. five subclasses of antibodies/immunoglobulins: IgG/A/M/D/E A. Differ in regard to polypeptides in heavy chains B. Antibody has two variable regions that combine w/ specific antigens. C. Antibodies + antigens promotes phagocytosis. II. Antigen-antibody complexes complement system. A. Complement fixation-proteins attach to mem.; promotes cell death B. Free complement proteins promote opsonization / chemotaxis and stimulate release of histamine from tissue mast cells. III. Specific and nonspecific immune mechanisms cooperate in the development of a local inflammation. Active and Passive Immunity I. Primary response first exposed to pathogen A. Primary - IgM antibodies made slowly, and person likely to be sick B. Secondary - IgG antibodies made quickly, able to resist pathogen. C. Active immunizations – “vaccinations” D. Secondary bc of development of lymphocyte clones as result of antigen-stimulated proliferation of appropriate lymphocytes. II. Passive immunity-transfer of antibodies from immune to non organism A. Passive immunity occurs naturally in mother to fetus. B. Antiserum injections - passive to some pathogenic organisms/toxins. III. Monoclonal antibodies made by hybridomas (formed artificially by fusion of B lymphs w/ multiple myeloma cells) Functions of T lymphocytes I. Thymus processes T lymph/secretes hormones required for effective immune response of T lymphocytes throughout body. II. Three subcategories of T lymphocytes. A. Killer T lymph kill victim cells by w/o antibodies but requires close contact bt killer T cell and victim cell. B. Killer T lymph responsible for transplant rejection, immunological defense vs fungal/viral infections, defense vs some bacterial infections. C. Helper T lymph stimulate, suppressor T lymph suppress function of B lymph/killer T lymphocytes. D. T lymph secrete lymphokines- promote action of lymph/macrophages. E. Receptor proteins on T lymph cell mem bind to foreign antigen in combination w/ histocompatibility antigen for T cell to become activated. F. Histocompatibility antigens (MHC molecules)- molecules on cell mem present in different combinations in different individuals. III. Antigen presenting cells (macrophages/dendritic cells)
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This note was uploaded on 03/20/2012 for the course MCB 32 taught by Professor Smiley during the Fall '11 term at Cal Poly.

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Final MCB Study Guide - Chapter 15 - Defense Mechanisms I....

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