The Cardiac Cycle

State: The cardiac cycle is composed of five stages which each trigger the relaxation or contraction of the atria or ventricles and direction of blood flow.

Elaborate: The cardiac cycle of the heart is divided into diastole and systole stages. Diastole refers to the period of relaxation experienced by the atria and ventricles. Systole is the contraction of the atria and ventricles. The pattern of blood flow starts in the left atrium to right atrium then into the left ventricle and right ventricle. During its course, blood flows through the mitral and tricuspid valves. Simultaneously, the right atrium is granted blood from the veins through the superior and inferior vena cava. The job of the superior vena cava is to transport de-oxygenated blood to

When your heart beats, the first beat represents the AV valves closing to prevent the backflow of blood into the atrium. The second beat is the semilunar valves opening to allow blood into the aorta or pulmonary trunk. The cardiac cycle is composed of five stages. These stages are atrial systole, early ventricular systole, late ventricular systole, early ventricular diastole, and late ventricular diastole. In order for atrial systole to occur, the blood that has been flowing between the atrium and ventricle via the opened atrioventricular valves must be deposited into the ventricles. The SA node is responsible for the contraction of the atrial myocardium. Once the atrium contracts, blood cannot flow back into or enter the atria because the openings of the great veins has been narrowed by pressure. The ventricles are now filled with blood accomplishing end-diastolic volume which is another term for how much blood your ventricles can contain while your body is at rest. The next phase is early ventricular systole. Now that all the blood is in your ventricles, it must continue onward to the