cardiac cycle
Quick Summary
The cardiac cycle describes the sequence of events in a single heart beat. It involves two main phases: systole and diastole.
Systole is the period of heart muscle contraction. During ventricular systole, the heart's ventricles contract, ejecting blood into the aorta and pulmonary trunk. This phase is marked by the peak of arterial blood pressure. Atrial systole, occurring later, completes the filling of the ventricles.1
Diastole is the period of relaxation. The heart muscle relaxes, allowing the chambers to fill with blood. Diastole is typically longer than systole, providing rest for the heart between contractions.2
The rhythmic beating of the heart is an intrinsic property of cardiac muscle, regulated by specialized nodes that generate and conduct electrical impulses, ensuring coordinated contractions. Heart valves ensure blood flows in only one direction, preventing backflow.345
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heartThis process is called the cardiac cycle. The period of relaxation is called diastole. The period of contraction is called systole. Diastole is the longer of the two phases so that the heart can rest between contractions. In general, the rate of heartbeat varies inversely with the size of the…
Read MoreThis process is called the cardiac cycle. The period of relaxation is called diastole. The period of contraction is called systole. Diastole is the longer of the two phases so that the heart can rest between contractions. In general, the rate of heartbeat varies inversely with the size of the…
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Read MoreThe cardiac cycle is defined as the time from the end of one heart contraction to the end of the subsequent contraction and consists of a period of relaxation called diastole followed by a period of contraction called systole. During the entire cycle, pressure is maintained…
Read More