PHGY 313 Lecture Notes - Antiserum, Toxicodendron Radicans, Cardiac Output
Document Summary
Hypersensitivity reaction: an over-reacting immune response that causes injury: the reaction is stimulated by an antigen that shouldn"t hurt you. About 50 million americans suffer from allergies, a type of hypersensitivity reaction. When you have an allergic reaction, you usually have compound reactions with 2 or more different allergens: for example, dust mites, ragweed, or dog hair. Other common sources of allergens are given in fig 1. Allergic rhinitis and asthma fall in this category: antibody mediated: antibodies bind to target antigens on the surface of cells. They activate the complement system or bind to receptors and alter signalling: immune complex disease: bacterial toxin is bound by igg in the circulation. Normally complement is fixed to a cluster of antigen, tagging it for removal by macrophages. If the clearance is inefficient, the immune complexes can travel through the circulation and deposit on walls of blood vessels and glomeruli.