Osmosis video - Cardiac cycle

The cardiac cycle is a repeating process by which the heart pumps blood into circulation. It consists of two phases: the diastole (relaxation) phase and the systole (contraction) phase.

During diastole, major events include isovolumetric ventricular relaxation and ventricular filling, which enables the heart to relax and ventricles to get filled with blood. During systole, the main events are isovolumetric ventricular contraction and systolic ejection, meaning the heart contracts and pumps the blood out of the ventricles.