systole

/ˈsɪstəli/

During a heartbeat, the heart contracts and pumps blood into the aorta, a phase known as systole.

In Greek, systole means "a drawing together or contraction." The rhythmic, repeated contraction of the heart muscle during systole is what allows it to push blood throughout the body. It's also part of what gets measured when you have your blood pressure taken: systolic blood pressure measures the force of the blood as it's being pumped into your arteries.

Definitions of systole

1. noun

   the contraction of the chambers of the heart (especially the ventricles) to drive blood into the aorta and pulmonary artery
   types:

   extrasystole

   a premature systole resulting in a momentary cardiac arrhythmia

   type of:

   beat, heartbeat, pulsation, pulse

   the steady contraction and expansion of the arteries with each beat of the heart