Question

Which of the following statement is correct about the given diagram of cardiac cycle?

• A. In q, semilunar valves remain closed
• B. In R, First heart sound appears
• C. In S, rate of filling of ventricles is not equal to the rate of flow of blood of atria
• D. duration of 'p' -phase is 0.1 sec.

Answer 1

The correct option is D duration of 'p' -phase is 0.1 sec.

1. Q represents the stage of ventricular systole when blood is pumped into the pulmonary artery and aorta respectively through the semi-lunar valves. So, they remain open.

2. First heart sound, 'lubb' occurs at the end of the P phase (atrial systole).

3. In S, joint diastole, rate of filling of ventricles is equal to the rate of flow of blood of atria.

4. P represents atrial systole and it occurs for a duration of 0.1 seconds.

So, the correct option is 'duration of 'p' -phase is 0.1 sec'.