BIOL 1221 Lecture Notes - Lecture 10: Pulmonary Circulation, Coronary Circulation, Pulmonary Artery
22 Jun 2017
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Myogenic controls the systemic blood pressure for individual organs, so it does not fluctuate and. Myogenic control (physical control) controlling the smooth muscle. Occurs when short-term autoregulation cannot meet tissue nutrient requirements: long-term autoregulation may take weeks or months to increase blood supply. Number of vessels to region increases ( angiogenesis ), and existing vessels enlarge. Common in heart when coronary vessel occluded, or throughout body in people in high-altitude areas. Skeletal muscle dilate when the blood flow increases. Blood flow varies with fiber type and activity. At rest, myogenic and neural mechanisms predominate. Blood flow increases in direct proportion to the metabolic activity (active or exercise hyperemia) Muscle blood flow can increase 10 or more during physical activity. Constant flow of blood in the brain is necessary because it can not withstand inadequate supply of oxygen. The brain has mechanical and myogenic mechanisms that protect it from changes in bp that could cause damage.
