What phase of the cardiac cycle is the heart in when all four valves of the heart are closed and ventricular pressure is building, but is not yet great enough to open a valve?
A) ventricular filling
B) isovolumetric relaxation
C) isovolumetric contraction
D) ventricular ejection
E) none

Question

Quizplus · Accepted Answer

Isovolumetric contraction is the phase in the cardiac cycle where the ventricles are contracting, but all four valves (the two atrioventricular valves and the two semilunar valves) are closed. This occurs right after the closure of the atrioventricular valves and before the opening of the semilunar valves, leading to an increase in ventricular pressure without a change in volume.

What Phase of the Cardiac Cycle Is the Heart in When