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44 Cards in this Set
- Front
- Back
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2 types of immunity
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innate (genetically determined, present at birth); acquired (active-follows exposure to antigen; passive-from transfer of antibodies from outside source)
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4 general characteristtics of immunity
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specificity; versatility; memory; tolerance
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properties of specific immunity
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specificity (t and b cell membrane receptors recognize a unique antigen); versatility (responsive to millions of antigens); memory (memory cells recall earlier encounters with an antigen); tolerance (ignores body's own antigens)
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purpose is to inactivate or destroy...
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pathogens, abnormal cells, and foreign molecules
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immune response is based on
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activation of lymphocytes by specific antigens by antigen recognition
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T Cell Activation
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antigens processed by macrophages; fragments form comples with MHC proteins on cell surface; T cell recognizes MHC complex, or; viral antigens on infected body cells; activated T cells differentiate further
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roles for activated T cells
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cytotoxic (killer) T cells-provide cell-mediated immunity; memory T cells-remember activating antigen; suppressor T cells-suppress other T and B cells; helper T cells-secrete regulatory cytokines
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B cells and antibody-mediated immunity
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b cells are first sensitized by exposure to their antigen; helper t cells for that antigen then activate those b cells; activated b cells divide to form: plasma cells (produce antibodies against that antigen) and memory cells
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antibody structure and function
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two pairs of parallesl polypeptide chains; four fixed segments (basic structure); four variable segments (specific antigen-binding structure); antigen-antibody complex forms (antigen determinant site binds to antibody)
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5 classes of antibodies
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lgG, lgM, lgA, lgE, lgD
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immunoglobin G
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lgG; resistance to pathogens
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immunoglobin M
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lgM; first antibody secreted
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immunoglobin A
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lgA; found in glandular secretions
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immunoglobin E
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lgE; stimulates inflammation
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immunoglobin D
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lgD; found on surface of B cells
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how antibodies can eliminate antigens
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neutralization; precipitation; agglutination; complement activation; attraction of phagocytes; stimulation of phagocytosis; stimulation of inflammation
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primary immune response
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antibodies produced by plasma cells after first exposure to antigen
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secondary immune response
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max antibody levels produced by subsequent exposure to the same antibody
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immune system hormones
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interleukins (IL: sensitize T cells, stimulate B cells, enhance non-specific defenses); interferons (slow spread of viruses locally); tumor necrosis factors (TNF: slows growth, kills tumor cells); phagocytic regulators
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immune disorders
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autoimmune disorders (mistaken attack on body's own tissues); immunodeficiency diease (disease/congenital block of immunity...aids); allergies (inappropriate or excessive response to allergens); age-related loss of effectiveness
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pathogens
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organisms that cause disease
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lymphatic system
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cells, tissues, and organs that play a central role in body's defenses against pathogens
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lymphatic system consists of...
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vessels filled w/lymph connected to lymphatic organs
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lymphatic system functions
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produce, maintain, distribute lymphocytes (which attack invading organisms, abnormal cells, foreign proteins); maintain blood volume; help eliminate local variations in interstitial fluid concentration
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lymphatic vessels
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lymph flows inside; begin as lymphatic capillaries in the tissues; lymph empties into venous system (at thoracic duct, at right lymphatic duct)
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3 classes of lymphocytes
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T cells (thymus dependent); B cells (bone marrow derived); NK cells (Natural Killer)
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types of T lymphocytes
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cytotoxic T cells (provide cell-mediated immunity, attack foreign and virus-infected cells); regulatory T cells (helper t cells and suppressor t cells)
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B lymphocytes...
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can become plasma cells (specific to a particular antigen; produce antibodies that react w/that antigen; antibodies are immunoglobulins); responsible for humoral or antibody-mediated immunity
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NK lymphocytes...
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provide immunological surveillance, attack cells (foreign/virally-infected/cancerous cells)
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lymphocyte life cycle
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`continuously migrate btwn lymphoid tissues and blood; production and dvlpmnt (lymphopoiesis) involves: bone marrow, thymus, peripheral lymphoid tissues
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lymphoid nodules...
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consists of loose connective tissue containing densely packed lymphocytes, tonsils are lymphoid nodules in the pharynx wall
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lymphoid organs...
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lymph noodes, thymus, spleen; located in areas that are vulnerable to pathogens
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lymph nodes...
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encapsulated masses of lymphoid tissue containing lymphocytes; monitor and filter lymph; remove antigens; initiate immune response
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the thymus...
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lies behind the sternum; t cells divide and mature there; shrinks after puberty; produces thymosins (hormones that regulate t cell dvlpmt)
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the spleen...
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white pulp (resembles lympoid nodules; removes antigens; initiates immunes response); red pulp (contains RBCs, recycles damaged or out-dated RBCs, stores iron from recycled RBCs)
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non-specific defenses protect against
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any threat
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specific defenses protect against
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particular threats and responds to antigens
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physical barriers...
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skin, hair, skin secretions, digestive epithelia and secretions
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phagocytes...
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microphages (neutrophils, eosinophils); macrophages
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immunological surveillance
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NK cells; find, kill cancer and virus-infected cells
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interferons
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small proteins released by virus infected cells; cytokines that trigger release of anti-viral proteins that inhibit virus production
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complement system
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complex system of proteins (initiate chain reaction..pos. feedback; destroy target cell membranes; stimulate inflammation, attract phagocytes)
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inflammatory response
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coordinated non-specific response to tissue injury
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fever
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temp greater than 99 degrees; inhibits pathogens; accelerates metabolism
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