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Chapter 17 GENE
Genetics Chapter 17 Human Heredity
Question | Answer |
---|---|
Pathogens | Disease- causing agents such as viruses, bacteria, fungi, and parasites |
Skin | A barrier, organisms set up conditions unfavorable to pathogens |
Innate | Broad , against bacteria in general |
Adaptive | Specificity, memory, vertebrates |
Three defenses against infection | Skin, inflammation, and the immune response |
Complement System | A chemical defense system that kills microorganisms directly, supplements the inflammatory response, and works with (complements) the immune system |
Membrane Attack Complex | Part of complement cascade, invade microorganism's plasma membrane, create pores through which fluids can flow, creating pores that eventually burst the microorganism |
Inflammation | Redness Pain Heat Swelling, body's reaction to invading microorganisms, nonspecific active defense system |
Histamine | A chemical signal produced by mast cells that triggers dilation of blood vessels |
Genetic predisposition to Crohn disease | Chromosome 16, Chronic inflammation, inflammatory bowel disease (like ulcerative colitis) |
Immunity | Terrific when targeted at bad guy, but bad when targeted at you. REGULATION IS KEY. |
Specific responses (Adaptive) | Antibody mediated immunity, and Cell mediated immunity |
Antibody- mediated immunity | Regulated by B cells and antibody production |
Cell-mediated immunity | Controlled by T cells |
Antibodies three main functions | 1. Bind to things, Neutralize 2. Opsonize- flag something for a macrophage to eat 3. Kick off complement cascade |
Lymphocytes | White blood cells that originate in bone marrow and mediate the immune response |
Stem Cells | Cells in bone marrow that produce lymphocytes by mitotic division |
B cell | A type of lymphocyte that matures in the bone marrow and mediated antibody- directed immunity, only makes one type of antibody |
T cell | A type of lymphocyte that undergoes maturation in the thymus and mediates cellular immunity. Programmed in the thymus to produce unique T-cell receptors |
Antibodies | Y shaped proteins produced by B cells that bind to specific foreign molecules antigens and inactivate them. Secreted by effector cells |
Antigens | Molecules that initiate antibody production, carried or produced by microorganisms |
T- cell receptors | Unique proteins on surface of the T cells that bind to specific proteins on the surface of cells infected with viruses, bacteria, or intracellular parasites |
Binding to an antigen stimulates | B or T cell to divide, producing many clones with the same antibody or TCR - Most polymorphic locus |
Major hisocompatability complex | Genes on chromosome 6 that encode recognition molecules that prevent the immune system from attacking a body's own organs and tissues. |
Antibody- mediated immunity (Humoral) | Immune reaction mediated by B cells that protects against invading viruses and bacteria using antibodies produced by plasma cells |
Cell- mediated immunity | Immune reaction mediated by T cells directed against body cells that have been infected by viruses or bacteria |
Helper T cell | Stimulates production of antibodies by B cells when an antigen is present. Stimulates division of B cells and cytotoxic T cells |
Antigen detection | B cells bind to antigens and become antigen presenting cells |
Activation of helper T cells | Activated helper T cells identify and activate specific B cells |
Antibody production by B cells | Activated B cells form two types of daughter cells: effector cells and memory B cells |
Effector cells | Daughter cells of B cells, which synthesize and secrete 2,000 to 20,000 antibody molecules per second into the bloodstream |
Memory B cell | A long- lived B cell produced after primary exposure to an antigen that plays an important role in secondary immunity |
Immunoglobulins | Five classes of proteins to which antibodies belong ( IgG IgA IgE IgM IgD) |
Cytokines | Made by T cells |
Suppressor T cells | Stop immune responses of B cells, other T cells |
Cytotoxic "killer" T cells | Secrete perforin to destroy infected body cells, and directly attack viruses, bacteria, cancer cells and transplanted organs |