The Cardiac cycle

is the series of events that occur in the heart during a single heartbeat. It includes the contraction of the heart muscle (systole), the relaxation of the heart muscle (diastole), and the filling and emptying of the heart chambers. The cardiac cycle is regulated by electrical impulses that travel through the heart, causing it to contract and relax. The cardiac cycle helps to ensure that the body’s cells and organs receive the oxygen and nutrients they need.