EVERYDAY SCIENCE

Detailed explanation-1: -Diastole begins with the closing of the aortic valve (or pulmonic) and ends with the closing of the mitral valve (or tricuspid). This period encompasses the ventricular relaxation and filling. Diastole represents when the blood vessels return blood to the heart in preparation for the next ventricular contraction.

Detailed explanation-2: -The period of relaxation is called diastole. The period of contraction is called systole. Diastole is the longer of the two phases so that the heart can rest between contractions.

Detailed explanation-3: -Systole is the contraction phase of the cardiac cycle, and diastole is the relaxation phase.

Detailed explanation-4: -Diastole is the period of the cardiac cycle that encompasses ventricular relaxation, passive and active filling of blood into the heart, and the period just prior to ejection.

Detailed explanation-5: -filling occurs during diastole, which has 4 phases: (1) isovolumic relaxation; (2) rapid filling phase; (3) slow filling, or diastasis; and (4) final filling during atrial systole (atrial kick.)