What happens to the ventricles during the cardiac cycle just before they relax?

During the cardiac cycle, just before the ventricles relax, they are in the process of contraction, known as systole. This is when the ventricles actively pump blood out of the heart — the left ventricle sends oxygenated blood into the aorta to circulate throughout the body, while the right ventricle pumps deoxygenated blood into the pulmonary arteries towards the lungs for oxygenation.

As the ventricles contract, they build pressure, which is essential for the effective ejection of blood. Following this phase of contraction, the ventricles will then enter diastole, where they will relax and begin to fill with blood again. Understanding this sequence is crucial, as it illustrates the mechanical actions of the heart and the importance of ventricular contraction in maintaining circulation.