APPLIED RADIOLOGICAL ANATOMY

Detailed explanation-1: -As soon as the ventricular pressure falls bellow the atrial pressure, the atrioventricular valves open. Blood flows rapidly from the atria to the ventricles. The semilunar valves are closed (fig. 4.1).

Detailed explanation-2: -The aortic valve closes when left ventricular pressure falls below aortic pressure, and momentum briefly maintains forward flow despite greater aortic than left ventricular pressure. Ventricular pressure then declines exponentially during isovolumetric relaxation, when both the aortic and mitral valves are closed.

Detailed explanation-3: -When the ventricles relax, atrial pressure exceeds ventricular pressure, the AV valves are pushed open and Page 2 blood flows into the ventricles. However, when the ventricles contract, ventricular pressure exceeds atrial pressure causing the AV valves to snap shut.

Detailed explanation-4: -After atrial systole, as the left atrium relaxes, its pressure decreases below the LV pressure, causing the mitral valve to begin closing. The beginning of systole produces a rapid increase in the LV pressure that seals the mitral valve and ends diastole.