Question

required information
the semilunar valves close during
multiple choice
ventricular systole
ventricular diastole
a trial systole
a trial diastole
both a trial and ventricular systole

Explanation:

During ventricular diastole, the ventricles relax. As the pressure in the ventricles drops below the pressure in the arteries (pulmonary artery and aorta), the semilunar valves (pulmonary valve and aortic valve) close to prevent back - flow of blood from the arteries into the ventricles. In ventricular systole, the semilunar valves open. During atrial systole and diastole, the state of the semilunar valves is mainly related to ventricular pressure changes rather than atrial activity directly. And the situation of both atrial and ventricular systole is not the time when semilunar valves close.

Answer:

ventricular diastole