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Unformatted text preview: PowerLecture: Chapter 39 Immunity Section 39.0: Weblinks and InfoTrac See the latest Weblinks and InfoTrac articles for this chapter online Videos: CNN Ask your Thomson Sales Representative for these volumes on CD or VHS Biology, 2003, Vol. 7, Global AIDS (2:18) Biology, 2002, Vol. 6, Small-pox Threat (5:12) Impacts, Issues: The Face of AIDS By 2004, AIDS had killed about 20 million in Africa, leaving 12 million children orphaned At least 40 million are presently infected with HIV, the virus that causes AIDS We are still without a vaccine Impacts, Issues: The Face of AIDS The first vaccine was against smallpox Edward Jenner injected cowpox material into the arm of a healthy boy, and six weeks later injected smallpox material The cowpox induced immunity to smallpox because the two are closely related Impacts, Issues: The Face of AIDS Pasteur demonstrated that heating could kill microorganisms in food and beverages Koch linked a microorganism with a specific disease (anthrax) Impacts, Issues Video Section 39.1: Weblinks and InfoTrac See the latest Weblinks and InfoTrac articles for this chapter online Three Lines of Defense Barriers at body surfaces Nonspecific responses Immune responses Innate and Adaptive Immunity Chemical Weapons in Immunity Section 39.2: Weblinks and InfoTrac See the latest Weblinks and InfoTrac articles for this chapter online Barriers at Body Surface Intact skin and mucous membranes Lysozyme Normal bacterial flora Flushing effect and low pH of urine Barriers at Body Surface Nonspecific Responses Lymph nodes trap and kill pathogens Natural killer cells attack a range of targets Inflammation Complement System Plasma proteins that take part in both specific and nonspecific response Activation of one triggers cascade of reactions that activate others Section 39.3: Weblinks and InfoTrac See the latest Weblinks and InfoTrac articles for this chapter online Attack Complexes Attack Complexes Complement proteins Acute Inflammation Nonspecific response to foreign invasion, tissue damage, or both Destroys invaders, removes debris, and prepares area for healing Characterized by redness, swelling, warmth, and pain Inflammation Mast cells release histamine Capillaries dilate and leak Complement proteins attack bacteria White cells attack invaders and clean up Inflammation Inflammatory response Section 39.4: Weblinks and InfoTrac See the latest Weblinks and InfoTrac articles for this chapter online Features of Immune Responses Self/nonself recognition Specificity Diversity Memory Memory and Effector Cells When a B or T cell is stimulated to divide, it produces more than one cell type Memory cells - set aside for future use Effector cells - engage and destroy the current threat Steps in Immune Response Recognition of an antigen Rounds of cell division that form huge populations of lymphocytes Specialization of lymphocytes into effector and memory cells that have receptors for one kind of antigen Key Components of Immune Response MHC markers Antigen-presenting cells T cells B cells Natural killer cells Formation of Antigen-MHC Complex Antigens “Nonself” markers on foreign agents and altered body cells such as tumors Trigger division of B and T cells Interactions Between Responses Immune Responses Immune responses Lymphocyte Battlegrounds Lymphatic System Human lymphatic system Section 39.5: Weblinks and InfoTrac See the latest Weblinks and InfoTrac articles for this chapter online Antibody Structure Consists of four polypeptide chains Certain parts of each chain are variable; impart antigen specificity Antibody Structure Antibody structure 5 Classes of Immunoglobulins Overview of Interactions Antigen-Receptor Diversity Gene sequences get shuffled, extensively and randomly, before they are expressed Each B cell or T cell bears only one type of antigen receptor Antigen Receptor Diversity Gene rearrangements Section 39.6: Weblinks and InfoTrac See the latest Weblinks and InfoTrac articles for this chapter online Antibody-Mediated Response Carried out by B cells Targets are intracellular pathogens and toxins Antibodies bind to target and mark it for destruction by phagocytes and complement Clonal Selection Clonal Selection Clonal selection of a B cell Immunological Memory Memory cells specific for an antigen are quickly activated to divide upon subsequent exposure to that antigen Immune Memory Immune Memory Antibody-Mediated Response Antibody-Mediated Response Antibody-mediated response Section 39.7: Weblinks and InfoTrac See the latest Weblinks and InfoTrac articles for this chapter online Cell-Mediated Response Cell-Mediated Response Cell-mediated response Antibody-Mediated Response Cell-mediated response Organ Rejection Cytotoxic T cells can contribute to rejection They recognize a portion of the donor cell’s MHC complex as self, view a portion as foreign Treat the combination as an antigen-MHC complex and attack donor cells Section 39.8: Weblinks and InfoTrac See the latest Weblinks and InfoTrac articles for this chapter online Videos: CNN Ask your Thomson Sales Representative for these volumes on CD or VHS A&P, 2003, Vol. 7, Custom Cancer Vaccine (3:10) Monoclonal Antibodies Manufacture antibodies against tumor-specific antigens First created by fusing antigen-producing B cells from mice with cells from B cell tumors Now made in genetically engineered cells Lymphokine-Activated Killers Lymphocytes are extracted from tumors Extracted cells are exposed to a lymphokine, an interleukin Large population of tumor-infiltrating, activated lymphocytes is then reinjected into patient Section 39.9: Weblinks and InfoTrac See the latest Weblinks and InfoTrac articles for this chapter online Videos: CNN Ask your Thomson Sales Representative for these volumes on CD or VHS A&P, 2004, Vol. 8, Whooping Cough Immunization (1:52) A&P, 2004, Vol. 8, Peanut Allergies (1:33) A&P, 2004, Vol. 8, Juvenile Arthritis (2:02) Immunization Process that promotes immunity Active immunization Antigen-containing material is injected Confers long-lasting immunity Passive Purified antibody is injected Protection is short lived Allergies Immune reaction to a harmless substance Genetic predisposition IgE responds to antigen by binding to mast cells and basophils These cells secrete the substances that cause symptoms Anaphylactic Shock A life-threatening allergic reaction Caused by the release of histamine by many mast cells and basophils Airways constrict and blood pressure drops as capillary permeability soars Autoimmune Disorders Immune system makes antibodies against self antigens Grave’s disease Myasthenia gravis Rheumatoid arthritis SCIDs Severe combined immunodeficiency Body’s ability to make lymphocytes is impaired or nonexistent High vulnerability to infection ADA deficiency is a heritable SCID Has been successfully treated using gene therapy Gene Therapy Section 39.10: Weblinks and InfoTrac See the latest Weblinks and InfoTrac articles for this chapter online Videos: CNN Ask your Thomson Sales Representative for these volumes on CD or VHS A&P, 2002, Vol. 6, AIDS Update (2:10) AIDS Combination of disorders that follows infection with HIV Includes Yeast (Candida) infections Pneumocystis pneumonia Karposi’s sarcoma Global Cases of AIDS/HIV HIV Life Cycle HIV Life Cycle HIV replication cycle T Cell Decline Release of new viral particles kills the host T cell The body is constantly making new T cells, but cannot outpace the rate of destruction As infection proceeds, T cell numbers inevitably decline Effect of T Cell Decline CD4 helper T cells play a vital role in immune function They are required for both cell-mediated and antibody-mediated immunity Infected individual becomes vulnerable to other infections, which eventually result in death Transmission of HIV HIV does not live long outside human body Most often spread by exchange of bodily fluids with an infected person In the U.S., anal intercourse and needle sharing are main modes of transmission Transmission of HIV Less commonly transmitted by vaginal intercourse and oral sex Can travel from mothers to offspring during pregnancy, birth, or breast-feeding Not known to be transmitted by food, air, water, casual contact, or insect bites Treatment No cure Once HIV genes are incorporated, no way to get them out AZT and other drugs slow the course of the disease and increase life span Researchers continue to develop drugs and to work toward an AIDS vaccine ...
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