What is ventricular diastole?

Ventricular diastole is the period during which the two ventricles are relaxing from the contortions/wringing of contraction, then dilating and filling; atrial diastole is the period during which the two atria likewise are relaxing under suction, dilating, and filling.

Is ventricular repolarization the same as ventricular diastole?

As pressure in the ventricles rises above two major arteries, blood pushes open the two semilunar valves and moves into the pulmonary trunk and aorta in the ventricular ejection phase. Following ventricular repolarization, the ventricles begin to relax (ventricular diastole), and pressure within the ventricles drops.

What happens during ventricular systole?

During systole, the two ventricles develop pressure and eject blood into the pulmonary artery and aorta. At this time the atrioventricular valves are closed and the semilunar valves are open. The semilunar valves are closed and the atrioventriular valves are open during diastole.

What happens to the heart during ventricular diastole?

At the start of the cycle, during ventricular diastole–early, the heart relaxes and expands while receiving blood into both ventricles through both atria; then, near the end of ventricular diastole–late, the two atria begin to contract (atrial systole), and each atrium pumps blood into the ventricle below it.

What causes ventricular systole?

Systole. Ventricular systole commences with the closure of the mitral and tricuspid valves once ventricular pressure exceeds atrial pressure. The closure of these valves causes the first heart sound.

What happens to ventricles during diastole?

During ventricular contraction, the atria relax (atrial diastole) and receive venous return from both the body and the lungs. Then, in ventricular diastole, the lower chambers relax, allowing initial passive filling of the thick-walled ventricles and emptying of the atria.

What are the two phases of ventricular systole?

The cardiac cycle is essentially split into two phases, systole (the contraction phase) and diastole (the relaxation phase). Each of these is then further divided into an atrial and ventricular component.

What is ventricular repolarization?

Repolarization in the ventricles of the heart is a process allowing the muscle cells of the ventricles to regain their ability to depolarize again. Repolarization entails movement of the ions, which entered the cell during the depolarization phase of the cycle, to flow out of the cell.

What happens at the end of ventricular diastole?

A small volume of blood flows directly into the ventricles from the venae cavae. Towards the end of ventricular diastole, any residual blood in the atria is pumped into the ventricle. The total volume of blood present in the ventricle at the end of diastole is called the end-diastolic volume or preload.

Which valves are closed during ventricular diastole?

The atrioventricular valves remain open while the semilunar valves are closed. During the middle part of a diastole a small volume of blood flows into the ventricles.