OVERVIEW OF THE IMMUNE SYSTEM
LYMPHATIC AND IMMUNE SYSTEM
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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when the body is exposed to a foreign substance and the immune system overreacts and harms the body
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inflammation of the lymph nodes
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enlargement of the spleen
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None of the above
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Detailed explanation-1: -Overview. Allergies occur when your immune system reacts to a foreign substance-such as pollen, bee venom or pet dander-or a food that doesn’t cause a reaction in most people. Your immune system produces substances known as antibodies.
Detailed explanation-2: -Hypersensitivity reactions are exaggerated or inappropriate immunologic responses occurring in response to an antigen or allergen. Type I, II and III hypersensitivity reactions are known as immediate hypersensitivity reactions because they occur within 24 hours of exposure to the antigen or allergen.
Detailed explanation-3: -There are four types of hypersensitivity reactions: type I is immunoglobulin E, or IgE mediated; type II is mediated by antibodies that activate cellular cytotoxicity, type III is mediated by immune-complexes, and type IV is a delayed T cell mediated hypersensitivity reaction.
Detailed explanation-4: -Type II hypersensitivity reaction refers to an antibody-mediated immune reaction in which antibodies (IgG or IgM) are directed against cellular or extracellular matrix antigens, resulting in cellular destruction, functional loss, or tissue damage.
Detailed explanation-5: -Type I: reaction mediated by IgE antibodies. Type II: cytotoxic reaction mediated by IgG or IgM antibodies. Type III: reaction mediated by immune complexes. Type IV: delayed reaction mediated by cellular response.