PHYS20008 Lecture Notes - Lecture 19: Pulmonary Valve, Heart, Circulatory System
21 Jul 2019
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Lecture 19: cardiovascular (2): cardiac cycle 16/04/19. Valves prevent back flow right heart delivers blood to lungs left heart delivers blood to systemic circulation the body. The right ventricle normally has less muscle mass than the left ventricle and creates less pressure when it contracts because: Pulmonary resistance is far less than systemic resistance its shorter -> less friction. Pump same volume per beat but right pumps with less pressure. Cardiac ventricles left ventricular wall thicker than right. Ventricles are contracting + blood pressure is high. Atria receives blood from periphery and have higher pressure than ventricles -> passive movement into ventricles. Atria systole: contraction of atria to move last bit into ventricles. Ventricles start to contract -> pressure increases -> closes valves so no back-flow into atria -> isovolumic contraction (volume isn"t changing because both valves are shut) -> building up pressure -> forces open the valves into the arteries.
