What is the definition of diastole in the context of heart function?

Diastole refers specifically to the phase of the cardiac cycle during which the heart's ventricles relax after contraction. This relaxation allows the chambers to fill with blood. In the context of heart function, during diastole, the ventricular muscles are not contracting, enabling the free flow of blood from the atria into the ventricles. This phase is crucial for maintaining adequate blood volume in the heart's chambers and ensuring proper circulation throughout the body.

Understanding the role of diastole is essential for grasping heart function, as it contrasts sharply with systole, the phase where the ventricles contract to pump blood out of the heart. This differentiation highlights the dynamic nature of the heart's operation, where relaxation and contraction work in harmony to maintain effective cardiovascular function.