Diastole

Early ventricular diastole is the filling of blood from the atria (from the left atrium shown in pink, and from the right atrium shown in blue) that weakly contract letting blood fill into the ventricles; in late ventricular diastole, the two atria begin to contract (atrial systole), forcing additional blood flow into the ventricles.

Diastole (/dˈæstəli/ dy-AST-ə-lee) is the relaxed phase of the cardiac cycle when the chambers of the heart are refilling with blood. The contrasting phase is systole when the heart chambers are contracting. Atrial diastole is the relaxing of the atria, and ventricular diastole the relaxing of the ventricles.

The term originates from the Greek word διαστολή (diastolē), meaning "dilation",[1] from διά (diá, "apart") + στέλλειν (stéllein, "to send").

  1. ^ Diastole. Merriam-Webster Online Dictionary. 24 August 2008.