What happens during diastole?

During diastole, the heart is in a phase of relaxation. This allows the chambers of the heart, especially the atria and ventricles, to fill with blood, as the heart does not contract during this time. This phase is vital for the heart's overall function as it enables the heart to rest and prepare for the next contraction.

When considering the choice about the artery walls, they do indeed return to a resting state after being temporarily expanded during the systolic phase of the cardiac cycle, when the heart contracts. During systole, the heart pumps blood into the arteries, which causes the walls to stretch. When the heart relaxes during diastole, the pressure in the arteries drops, allowing them to return to their resting size. This physiological response is crucial as it helps in maintaining an adequate blood flow and pressure throughout the circulatory system.

Conversely, the other options do not accurately describe what occurs during diastole: the heart does not contract (that involves systole), blood clots do not specifically form during this phase, and blood pressure does not peak; rather, it is at its lowest during diastole. Thus, focusing on the relaxation of the heart and the return of artery walls to their normal size captures