CLINICAL MEDICINE

Detailed explanation-1: -Atrial Diastole: In this stage, chambers of the heart are calmed. That is when the aortic valve and pulmonary artery closes and atrioventricular valves open, thus causing chambers of the heart to relax.

Detailed explanation-2: -Diastole is the relaxation phase of the heartbeat. During this phase, the ventricles relax and blood flows through the left and right atria from the vena cava and pulmonary veins. Systole is the contraction phase of the heartbeat.

Detailed explanation-3: -The heartbeat is caused by the heart muscles relaxing and contracting. During this cycle, the period of relaxation is called diastole and the period of contraction is called systole.

Detailed explanation-4: -Atrial diastole: lasting about 0.7 seconds-relaxation of the atria, during which the atria fill with blood from the large veins (the vena cavae). Ventricular diastole: lasts about 0.5 seconds-begins before atrial systole, allowing the ventricles to fill passively with blood from the atria.

Detailed explanation-5: -The cardiac cycle involves four major stages of activity: 1) “Isovolumic relaxation", 2) Inflow, 3) “Isovolumic contraction", 4) “Ejection". (See Wiggers diagram, which presents the stages, label-wise, in 3, 4, 1, 2 order, left-to-right.)