ACTIVE LOCAL HYPEREMIA Meaning and
Definition
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Active local hyperemia refers to an increased blood flow to a specific tissue or organ in response to increased metabolic activity or physiological demand. It is a normal physiological response that occurs in the body to compensate for increased cellular needs.
During active local hyperemia, the blood vessels leading to the active tissue dilate, allowing a larger volume of oxygenated blood to reach the area. This response is mediated by the release of chemical substances such as adenosine, nitric oxide, prostaglandins, and metabolic by-products, which act as vasodilators. These substances cause the smooth muscles in the walls of arterioles and capillaries to relax, resulting in increased blood flow within the tissue.
The purpose of active local hyperemia is to deliver sufficient oxygen and nutrients to meet the metabolic demands of the working tissue. This process is commonly observed in exercising muscles, where increased blood flow is necessary to supply nutrients and remove waste products, such as carbon dioxide and lactic acid.
Active local hyperemia is a beneficial response since it ensures that vital tissues receive an adequate blood supply to support their increased activity. It is often accompanied by a reddening of the affected area due to the higher concentration of oxygenated blood. However, if the hyperemia becomes excessive or persists for an extended period, it may indicate an underlying pathology or inflammation in the tissue.
