What is defined as diastole in cardiac physiology?

Diastole is defined as the relaxation phase of the heart muscle. During this phase, the heart chambers, specifically the atria and ventricles, fill with blood as the heart prepares for the next contraction. This is a critical part of the cardiac cycle, as it allows for adequate blood volume to be present for effective pumping during systole, which is the phase of contraction.

Understanding diastole is essential for recognizing the overall function of the heart and the importance of maintaining proper heart rhythms and function. Accurate identification of this phase can assist in diagnosing conditions related to heart performance and developing appropriate treatment plans.

The other options provided do not accurately describe diastole: one refers to the contraction phase, another describes the ejection of blood, and the last one pertains to the rate of heartbeats, all of which relate to different aspects of cardiac physiology.