Systole | Diastole | |
1 | It is the contraction of the heart chambers to drive blood into the aorta and the pulmonary artery. The aortic valve and the pulmonary valve remain closed during the systole while the semilunar valves remain open. | It is the relaxation of the heart chambers between two contractions. During diastole, the chambers are filled with blood. The filling of the atrial chamber is known as atrial diastole and filling of the ventricles is known as ventricular diastole. |
2 | Systole decreases the volume of the heart chambers and forces the blood out of them. | Diastole brings the heart chambers back into their original sizes to receive more blood. |