<P> The cardiac cycle is the performance of the human heart from the beginning of one heartbeat to the beginning of the next . It consists of two periods : one during which the heart muscle relaxes and refills with blood , called diastole ( die - ASS - toe - lee ) , followed by a period of robust contraction and pumping of blood , dubbed systole ( SIS - toe - lee ) . After emptying , the heart immediately relaxes and expands to receive another influx of blood returning from the lungs and other systems of the body -- before again contracting to pump blood to the lungs and those systems . A normally performing heart must be fully expanded before it can efficiently pump again . Assuming a healthy heart and a typical rate of 70 to 75 beats per minute , each cardiac cycle , or heartbeat , takes about 0.8 second to compete the cycle . </P>
<P> The cardiac cycle is the performance of the human heart from the beginning of one heartbeat to the beginning of the next . It consists of two periods : one during which the heart muscle relaxes and refills with blood , called diastole ( die - ASS - toe - lee ) , followed by a period of robust contraction and pumping of blood , dubbed systole ( SIS - toe - lee ) . After emptying , the heart immediately relaxes and expands to receive another influx of blood returning from the lungs and other systems of the body -- before again contracting to pump blood to the lungs and those systems . A normally performing heart must be fully expanded before it can efficiently pump again . Assuming a healthy heart and a typical rate of 70 to 75 beats per minute , each cardiac cycle , or heartbeat , takes about 0.8 second to compete the cycle . </P>
which part of the cardiac cycle represents the pumping of the heart muscle
which part of the cardiac cycle represents the pumping of the heart muscle
systole
systole