Which part of the heart is involved during diastole?

During diastole, the heart undergoes a phase of relaxation. This is when the chambers of the heart, specifically the atria and ventricles, relax and fill with blood. As the heart muscle relaxes, the pressure within the chambers decreases, allowing blood to flow in from the veins.

This filling phase is vital for ensuring that enough blood is present in the heart’s chambers before the next contraction occurs during systole. The proper functioning of diastole is essential for maintaining an adequate cardiac output and ensuring that the body's tissues receive the oxygen and nutrients they require.

Other options do not accurately describe the diastolic process. The contraction of muscle is related to systole, the stimulation of nerves pertains more to the electrical activity that initiates heart contractions, and the regulation of blood flow involves various mechanisms that are not specific to the relaxation of the heart muscle during diastole.