ANATOMY

Detailed explanation-1: -Table of Contents. systole, period of contraction of the ventricles of the heart that occurs between the first and second heart sounds of the cardiac cycle (the sequence of events in a single heart beat). Systole causes the ejection of blood into the aorta and pulmonary trunk.

Detailed explanation-2: -Systole is the contraction phase of the cardiac cycle, and diastole is the relaxation phase.

Detailed explanation-3: -During systole, the two ventricles develop pressure and eject blood into the pulmonary artery and aorta. At this time the atrioventricular valves are closed and the semilunar valves are open. The semilunar valves are closed and the atrioventriular valves are open during diastole.

Detailed explanation-4: -The cardiac cycle involves four major stages of activity: 1) “Isovolumic relaxation", 2) Inflow, 3) “Isovolumic contraction", 4) “Ejection".