What happens during diastole?

What happens during diastole?

• A. Relaxation of a heart chamber.
• B. Contraction of a heart chamber.
• C. Valves closing abruptly.
• D. Blood ejection.

Answer: (A)

During diastole, the heart muscle relaxes after a beat. The ventricles relax and fill with blood from the atria, with the atrioventricular valves (mitral and tricuspid) open to allow this flow while the semilunar valves (aortic and pulmonary) stay closed to prevent backflow. As filling progresses, there’s rapid filling followed by a slower phase, and toward the end of diastole the atria contract to top off ventricular filling. In short, diastole is the relaxation and filling phase of the cardiac cycle.

During diastole, the heart muscle relaxes after a beat. The ventricles relax and fill with blood from the atria, with the atrioventricular valves (mitral and tricuspid) open to allow this flow while the semilunar valves (aortic and pulmonary) stay closed to prevent backflow. As filling progresses, there’s rapid filling followed by a slower phase, and toward the end of diastole the atria contract to top off ventricular filling. In short, diastole is the relaxation and filling phase of the cardiac cycle.