NURS 3104 Study Guide - Quiz Guide: Tricuspid Valve, Heart Valve, Hemodynamics
18 Sep 2017
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An important determinant of blood ow in the cardiovascular system is the principle that uid. Ows from a region of higher pressure to one of lower pressure. The pressures responsible for blood ow in the normal circulation are generated during systole and diastole. Figure 26-5 depicts the pressure differences in the great vessels and in the four chambers of the heart during systole and diastole. Beginning with systole, the pressure inside the ventricles rapidly rises, forcing the av valves to close. As a result,blood ceases to ow from the atria into the ventricles, and regurgitation (backflow) of blood into the atria is prevented. The rapid rise of pressure inside the right and left ventricles forces the pulmonic and aortic valves to open,and blood is ejected into the pulmonary artery and aorta,respectively. The exit of blood is at rst rapid; then, as the pressure in each ventricle and its corresponding artery equalizes, the ow of blood gradually decreases.
