KINESIOL 1AA3 Lecture Notes - Lecture 5: Aortic Valve, Heart Valve, Mitral Valve
14 Sep 2016
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Document Summary
Period of ejection reflects lv kicking out pre-loaded blood. Pressure differences drives movement of blood throughout cv system. Only way into lv is through mitral valve from left atrium. Only way out of lv is to kick open aortic valve, bicuspid valve into aorta. Semilunar valves open: ventricular pressure exceeds aortic pressure. During very short window in which ventricle is contracting and there is no change in blood volume, pressure jumps up considerably ventricular pressure is generated not from volume of blood but from state of myocardial cells. Lv stretches aorta during period of ejection myogenic response (causes aorta to stretch) Recoil helps push blood into general circulation but slams blood back into closed valve. Major contributor to ventricular pressure: contracted state of myocardial cells opens aortic valve. During isovolumetric period, ventricle contracts but aortic valve stays closed until we get to critical crossover point. Semilunar valve open sup when pressure inside exceeds outside.
