BLD 204 EXAM 2 QUESTIONS AND ANSWERS WITH
COMPLETE SOLUTIONS GRADED A++
immunity protection against infection. Freedom from a harmful condition. The system is made up of the cells and molecules that defend the body against pathogens -recognition of nonself -highly specific response to nonself -memory characteristics of human immunity antigens molecules recognized as nonself, the part recognized is called an epitope. They can be endogenous (native to the host) or exogenous (environmental) innate immunity immunity made up of cells and molecules that are always ready to provide a defense against invaders. Not antigen specific adaptive immunity immunity made up of cells and molecules that can respond to the "microbes that go away" from innate protection. Specific and powerful. Humoral (antibody) and cell mediated Primary lymphoid tissue 1 / 3
includes the thymus and bone marrow. Cells differentiate and mature into lymphocytes here secondary lymphoid tissue includes the lymph nodes, spleen and malt. Adaptive immune responses develop here -epithelial barriers -pH -phagocytes -NK cells -circulating proteins (complement, etc...) what are innate components?natural killer cells cytotoxic lymphocytes which recognize loss of MHC class I "self" molecules on cells that are malignant or virus infected. They produce cytokines T cells cells that are thymus derived, early in life the thymus shrinks after puberty. They are found in the blood, spleen and around arterioles and lymph node inter-follicular zones.They don't detect free antigens, they have to be presented to them by MHC molecules.They are involved in cell mediated immunity cytotoxic T cells (CD8+) T cells involved in cell mediated immunity. MCH class I presents antigen to these cells.The CD8+ T is activated and interacts with cell that presents the antigen. It stimulates apoptosis in the infected cell an also produces and releases cytokines Helper T cells (CD4+) 2 / 3
T cells that are for antibody response (humoral mediated response) working along with antigen presenting cells and B cells. They release cytokines which help stimulate B cells to make antibodies and encourage macrophages to destroy microbes.T cell receptors receptors that are membrane bound. They are two peptide chains that together form a binding site that recognizes a unique antigen. The variability is created by rearrangements of gene segments called V,D,J -presented on all nucleated cells -signal to CD8+ cytotoxic T cells -heavy alpha chain and beta2 microglobulin chain what type of cells have MHC class I? What type of cell do they signal to? What type of chains are they made of?-presented on macrophages, dendritic cells and B cells -signal to CD4+ helper T cells -two peptide chains of more equal size what type of cells have MHC class II? what type of cell do they signal to? What type of chains are they made of?gamma delta T cells T cells that have a different T cell receptor, it is not alpha beta. There is no CD4 or CD8.Don't seem to recognize protein epitopes, they recognize lipids instead. Their numbers are relatively low, mostly located in the mucosa.B cell
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