What is the phase of ventricular contraction called?

The phase of ventricular contraction is referred to as systole. During systole, the ventricles of the heart contract, pumping blood out of the heart and into the aorta and pulmonary arteries. This process is crucial for maintaining circulation throughout the body.

The contraction results from electrical impulses that cause the myocardial cells (heart muscle cells) to depolarize and generate tension, ultimately leading to the ejection of blood. Systole is a vital component of the cardiac cycle, which also includes diastole, the phase of relaxation and filling of the heart chambers after contraction.

In contrast, diastole refers to the phase when the heart relaxes and the chambers fill with blood, preparing for the next contraction. Terms like "resting phase" and "contraction phase" do not specifically describe the distinct phase of ventricular contraction recognized in cardiac physiology. Hence, systole is the appropriate term for the phase when the ventricles contract.