Question

The diagram below represents a section of the human heart. Answer the question that follows:

Which parts of the heart are in the diastolic phase? Give a reason to support your answer.

Answer 1

Phases of heartbeat:

1. The heartbeat occurs in a rhythmic pattern. This helps the blood to be pumped throughout the body.
2. Systole is the contraction of heart muscles. This causes the blood to move from one chamber to the next chamber/ blood vessel.
3. Diastole is the relaxation of heart muscles. This causes the blood to be filled in the chamber.

Parts of the heart in the diastolic phase:

1. In the given image, the bicuspid valve and the tricuspid valves that are present between the atrium and ventricle are open. The semilunar valve between the ventricle and the blood vessels is closed.
2. The blood flow is shown to occur from the atrium to the ventricle. This happens when the ventricles are in the diastolic phase to accommodate blood from the atrium.
3. Thus the ventricles of the heart are in the diastolic phase in the given diagram.