Pathophysiology

Pathophysiology Study Guide

organs. Symptoms of this disease include swelling in the joints and organs, pain in joints, sensitivity to sun, and a rash. Treatment includes pain suppressors, non-steroidal anti-inflammatory drugs, immunosuppressors, corticosteroids, and changes in lifestyle that help to reduce exposure to sun, while having a balanced diet and reduction in stress level. Hypersensitivity Reactions Type I: Atopic Hypersensitivity or Anaphylactic Allergic Reaction Anaphylaxis, or type I hypersensitivity, is a whole-body, immediate hypersensitivity also known as anaphylactic shock. In this case, allergens enter the body tissues in the form of a concentration, like injections. Once the dosage has entered the body, the IgE type of immunity is generated by the plasma cells. Then, the antibodies travel in the bloodstream and thereby attach at the Fc of the antibody molecule and basophils in the blood. Once the reaction between the antigen and antibody takes place, then histamine and serotonin, which are physiologically active substances, are released from granules within the cell. Allergic reactions are likely to occur, which is known to be localized anaphylaxis. These localized reactions are induced by foods, pollen grains, and animal dander. Type II: Cytotoxic Hypersensitivity Cytotoxic reactions are a form of immediate hypersensitivity, sometimes referred to as type II hypersensitivity. When antigens react with the antibodies in the bloodstream, the immunity types IgE and IgM are generated. These reactions also take place on the surface of cells. The output of this reaction destructs the local tissue cells. For instance, in the case of thrombocytopenia, antibodies unite with antigens on the thrombocytes surface and then the complement gets activated, leading to the destruction of thrombocytes. It results in an impaired blood-clotting mechanism. These reactions are apparent by the transfusion reaction that happens with an improper transfusion of blood. Type III: Immune Complex or Arthus Reaction This type of hypersensitivity is caused by the combination of antibodies and antigens, which result in fixation of the complement. Antigens are in the form of fluid solutions that react with the antibodies of the type IgM or IgG. In this case, the nucleic acids or proteins are also involved. For instance, with serum sickness the serum of the animals is injected into the human body and in this event, the proteins obtain antibody production. When the reaction between the antibody and antigen takes place, immune complexes are formed and activated, which leads to the destruction of tissues of the body. Symptoms of hypersensitivity are edema of the face, hands, and feet and interference with normal functioning of the respiratory system. Some instances of the diseases due to type III immune complex hypersensitivity include systemic lupus erythematosus, rheumatoid arthritis, and glomerulonephritis. Type IV: Delayed Hypersensitivity In this type of hypersensitivity, the immune cells T-lymphocytes participate instead of the antibodies. Lymphokines are generated by these T-cells, which initiate macrophages and lead to phagocytosis. In this case, the immune system gets aggravated and the phagocytes cause the destruction of tissues of the body. This form of hypersensitivity is also known as delayed hypersensitivity, as the time taken

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