What is the action of the heart during the contraction phase called?

During the contraction phase of the heart, the term used to describe this action is systole. This is the phase in which the heart muscle contracts, pumping blood out of the chambers of the heart and into the arteries. Specifically, during systole, the ventricles contract to push blood into the aorta (from the left ventricle) and into the pulmonary artery (from the right ventricle).

It is important to understand the other terms as well, as they play a role in the heart’s overall function. Diastole refers to the phase when the heart muscle relaxes and the chambers fill with blood, which is distinctly different from systole. Contractility refers to the inherent strength and ability of the heart muscle to contract, but it does not specifically describe the phase of contraction itself. An electrocardiogram is a test that captures the electrical activity of the heart, but it is not the term used to describe the contraction phase. Thus, systole accurately identifies the heart's action during contraction, highlighting its crucial role in the cardiac cycle.