During systole, the auricles contract before the ventricles. The blood from the auricles reach the ventricles during contraction. After this, the ventricles contract. The blood from the right ventricle moves into the pulmonary artery to reach the lungs. From lungs, oxygenated blood comes into the left auricle during diastole and comes to the left ventricle during auricular systole. The blood from the left ventricle reaches the entire systemic circulation.

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