Infarct(redirected from Lateral medullary infarct)
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a focus of organ or tissue necrosis resulting from an interruption of the blood supply to the area. The direct causes of infarcts are thrombosis, embolism, or spasm of the arteries feeding this tissue. Hypoxia is a decisive factor in the development of the tissue changes associated with an infarct.
There are three types: white, or ischemic, infarct, which is a zone of necrosis lacking in blood; red, or hemorrhagic, infarct, in which the zone of necrosis is saturated with excessive blood; and ischemic infarct with a hemorrhagic zone. The first and third types of infarct are generally formed in the heart, kidneys, and spleen, and the second in the lungs and intestine. An infarct may be conical (kidney, lungs) or irregular (heart, brain) in shape. Its consistency varies with the nature of the necrosis, which may be dry (myocardial infarct) or moist (cerebral infarct).
Infarcts cause profound changes in the organs affected. The dead areas are resorbed or organized, resulting in the formation of a cyst (in the brain) or a scar (in the heart muscle), or they may suppurate and liquefy (septic infarct). The size, location, and properties of an infarct determine whether the affected organ becomes weakened or loses its functions.
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