MEDizzy - A 22-year-old second-year medical student develops a “red”

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General Pathology (I)

A 22-year-old second-year medical student develops a “red” face after being asked a question during lecture. Which of the following statements best describes this vascular reaction? \

ExplanationHyperemia refers to excess amounts of blood within an organ. It may be caused by increased arterial supply (active hyperemia) or impaired venous drainage (passive hyperemia). Examples of active hyperemia include increased blood flow during exercise, blushing (such as embarrassment associated with being asked a question during a lecture), or inflammation. Examples of passive hyperemia, or congestion, include the changes produced by chronic heart failure. These changes include chronic passive congestion of the lung or the liver. The lung changes are characterized by intra-alveolar, hemosiderin-laden macrophages, called “heart failure cells.” Congestion in the liver is characterized by centrilobular congestion, which is seen grossly as a “nutmeg” appearance of the liver. In contrast to hyperemia, hemorrhage refers to the leakage of blood from a blood vessel. Blood may escape into the tissue, producing a hematoma, or it may escape into spaces, producing a hemothorax, hemopericardium, or hemarthrosis. Superficial hemorrhages into the skin or mucosa are classified as petechiae (small, pinpoint capillary hemorrhages), purpura (diffuse, multiple superficial hemorrhages), or ecchymoses (larger, confluent areas of hemorrhages).