What occurs during the systole phase of the heart cycle?

During the systole phase of the heart cycle, the ventricles contract, resulting in the ejection of blood from the heart. This contraction is a critical part of the heartbeat where the pressure within the ventricles increases significantly, pushing blood either into the aorta to supply the rest of the body or into the pulmonary arteries to direct blood toward the lungs for oxygenation.

This phase is characterized by the rising pressure within the ventricles, which forces the semilunar valves (the aortic and pulmonary valves) to open, allowing blood to flow out of the heart. The effectiveness of this process is crucial for maintaining blood circulation throughout the body and ensuring that oxygen-rich blood reaches tissues and organs.

In this context, it is important to note the distinction between the systolic and diastolic phases of the heart cycle. The diastole phase involves the filling of the atria and ventricles with blood, while systole focuses specifically on the contraction and pumping action of the ventricles. Therefore, the emphasis on the ventricles contracting and sending blood to the body during systole underscores the important role this phase plays in maintaining hemodynamic stability.