Question Video: Describing the Diastole Phase of the Cardiac Cycle Biology • Second Year of Secondary School

Video Transcript

The cardiac cycle has two distinct phases, systole and diastole. Complete the following statement. The diastole phase occurs when the ventricles blank and the atrioventricular valves open.

As we know, the heart is responsible for pumping blood to the various organs of the body. The pumping action of the heart involves cycles of contractions and relaxations of the chambers of the heart. These chambers are the left and right atria and the left and right ventricles. The atrioventricular valves control the passage of the blood between each atrium and ventricle.

The period of complete relaxation of the ventricles is called diastole. This is when the blood contained in the atrium fills the ventricles after the opening of the atrioventricular valves. Then, the period of contraction of the ventricles is called the systole. This is when the blood is pumped out of the heart through the pulmonary artery and aorta.

Now, we can answer our question. The diastole phase occurs when the ventricles relax and the atrioventricular valves open.