Question

What is the state of heart in the interval after end of second heart sound and before beginning of first heart sound again ?

• A. Ventricle remain systole auricles undergo first diastole and the systole
• B. Ventricle remain in diastole, auricles undergoes first diastole and the systole
• C. Ventricles are in systole and then undergo diastole, auricles remain in diastole
• D. Ventricles remain in diastole, auricles remain in diastole

Answer 1

Answer: (D)

Ventricles remain in diastole, auricles remain in diastole

The $2^{nd}$ heart sound is an indication of the closure of semilunar valves of the pulmonary artery and aorta respectively to prevent the back flow of blood into the ventricles as the ventricles are in the process of undergoing relaxation or diastole. At this stage the auricles are also in the diastolic stage, this stage is also referred to as the joint diastolic stage.

So, the correct answer is 'Ventricles remain in diastole, auricles remain in diastole'