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hypersensitivity reactions
set of disorders that arise from an over-reaction of the immune system to an antigen's presence
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anaphylactic shock
- ex. of hypersensitivity reaction.
- -a process that begins with entry of an antigen into body; could be a diverse chemicals.
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anaphylactic shock, the process...
- immune system response to antigen and B cells revert to plasma cells, (IgE produced); antibody fixes itself to surface of mfast cells (connective tissue cell) and white blood cell (basophils)
- -molecules of IgE attach to thousands of mast cells and basophils and person becomes highly sensitve to antigen
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first priorities of treatment to anaphylaxis.
epinphrine, antihistamines, and smooth muscle relaxers
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allergy.
vast majority of reacdtions accompanied by limited production of IgE antibodies and sensitization in localized areas of body
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cytotoxic hypersensitivity.
- form of hypersensitivity rxn/immune system disorders
- -cell-damaging rxn that occurs when IgG antibodies react with antigens on surfaces of body cells. complement system often activated, and IgM antibodies may be involved.
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immune complex hypersensitivity
- third form of hypersensitivity rxn.
- when IgG antibodies combine excessively with antigens dissolved in body fluids
- -immune complexes(many antigen-antibody rxn) accumulate along blood vessels or on tissues surfaces.
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cellular hypersensitivity
- final immune disorder.
- exaggeration of process of cell-mediated immunity.
- delayed reaction, seen til 24-72 hrs laterr.
- accumulation of T cells in skin and overactivity of cells against offending antigen. T cells begin attack body cell, drying of skin, with reddening and scaling
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example of immune complex hypersensitivity.
butterfly rash, systemic lupus erythematosus (SLE)
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example of cytotoxic hypersensitivity
transfusion reaction arising from mixing of incompatible blood types
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