pathophysiology chapter 19
Terms
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- Innate or non \specific immune defence
-
1st line of defence. Rapid, Nonself Recognition. Skin, mucous membranes, phagocytes, antimicrobial molecules, inflamation, fever.
Cells:phagocytes(macrophages, neutrophils, NK, dendritic cells. - Adaptive or specific immunity
-
Slow. Very large. Specific to microbe and antigens. Nonself recognition. Memory, more rapid and efficient with subsequent exposure.
Cell killing tagging of antigen by antibody. T and B lymphocytes -
B cells.
Function, potential, maturation site. -
Mature in bone marrow.(can migrate to peyers patch
and spleen and liver for maturation) Responsible for humoral immunity. Can be transform (with T cell help) into memory B cells or antibody secreting plasma cells. - Antigen /Immunogen
- Substance foreing to host that can stimulate an immune response
- Antigens determinants or epitopes
- Molecular region on the surface of an antigen capable of eliciting an immune response and combining with specific antibodies. Antigens may contain multiple epitopes
- Haptens
- Antigen to small to stimulate an immune response unless combine with larger protein molecules
- Penicilling allergy, in relation to Haptens
- Penicillin is a hapten, in some individuals it can combine with large proteins andd cause an allergic reaction.
- Humoral immunity
- Immune responce by B cells, derived plasma cells ( antibodies), that travel in the blood and interact with circulating and surface cells
- Cell mediated immunity
- immune response mediate by T cells
- Class I MHC
- Present in virtually all nucleated cells. Present processed antigens to cytotoxic CD8 T cells, restric cytolysis to virus infected cells, tumor cells, and transplanted cells.HLA: HLA A, HLA B, HLA C.
- Class II MHC
- Present in immune cells, antigen representing cells, Bcells, and macrophages. Present processed antigenic fragments to CD4 T cells, necessary for interaction among immune cells
- T cells
- Arise from BM but migrate to thymus for their maturation
- IgG
- 75%. Displays antiviral, antitoxin, and antibacterial properties, only Ig that crosses the placenta, responsable for protection of newborn,activates complement and binds to macrophages.
- IgA
- 15%. Predominant Hg in body secretions, such as saliva, nasal and respiration secretion, and breast milk, protects mucous membranes.
- IgM
- 10%. Forms the natural antibodies such as those fo ABO blood antigens, prominent in early immune responses, activates complement.
- IgD
- 0.2%. Found in lymphocytes, needed for maturation of B cells.
- IgE
- 0.004%. Binds to mast cells and basophils, involve in parasitic infections, allergic and hypersensitive reactions.
- T-cells functions
- Activations of other T-cells and B-cells, in the control of intracellular viral infections, rejection of foreign grafts,in delayded hypersensitive reactions.
- Helper T-cells,
- CD4 helper T cell. "master regulator for the immune system". Activated by MHC II.
- T Cytotoxic cells
- CD8 cytotoxic T cells. Activated by MHC I,
- IgG in ralation to titers
- IgG class of antibodies increase during the acute phase and remains high during the acute phase and remains elevated until or beyond resolution.
- IgM in ralation to titers
- IgM specific antibodies generally rise and fall during the acute phase of the disease.
- Natural Killer cells
- NK cells kills foreing cells automatically, no activation needed, Kills cells by producing pore forming proteins,enzymes and toxic cytokines. Prone for virus infected cells.
- Central lymphoid organs
- Bone marrow, thymus, Provides environment for immune cell production and maturation.
- Peripheral lymphoid organs
- Lymph nodes, spleen, tonsils, appendix, Peyer's patch, mucosa associated lymphoid tissue in respiratory, GI and reproductive system. Trap and process antigens and promotes interaccion with mature immune cells.
- Thymus function
-
Generates mature T-cells.
Through thymic selection, selects only functional T-cells. - Spleen function
- Filters antigens from blood, important response in systemic infections.
- Interleukin-1
- Activates endothelium and lymphocytes, induces fever and acute phase responce, stimulates neutrophil production.
- Interferon
- Exerts antiviral activity in body cells, induces class I antigen expression, activates NK cells
- Tumor necrosis factor, TNF
- Induces inflamation, fever, and acute phase responce, activates neutrophils and endothelial cells, kills cells through apoptosis.
- Cytokines that are Major mediators in the imflammatory response
- Interleukin 1, IL6, and TNF
-
Cytokines in Hematopoiesis.
Colony stimulating factors - Cytokines that stimulate bone marrow pluripotent stem cells and progenitor to produce large numbers of plateles, erythrocystes, lymphocytes, neutrophils, monocytes, eosinophils, basophils and dendritic cells
- Active immunity
- Adquired by immunization or having the disease.
- Passive immunity
- Temporary, transfer of antibodies against an antigen. Fast acting, short term.
- Activation of complement systems results in:
-
Cytolysis
Opsonization
Chemotaxis
Anaphylaxis - The complement system is a primary effector for:
- Both innate and adaptive humoral immune response.
- Complement
-
soluble protein molecule.
can engage in cell distruction - Cytolysis
- Lysis and destruction of cell membranes of body cells or pathogens.
- Opsonization
- Coating of antigens so that it can be easily engulfed and digested by the macrophages and other phagocytic cell
- Chemotaxis
- Chemical attraction of neutrophils and phagopcytic cells to the antigen
- Anaphylaxis
- Activation of mast cells and basophils with release of inflamatory mediators that produce smooth muscle contaction and increase vascular permiability
- tolerance
- the ability of the immune system to be nonreactive to self antigens while producing immunity to foreing agents
- Immunoglobulin that crosses the placenta and provides immunity for the infant in the first 3 to 6 month of life
- IgG