Question

which of the following is the correct sequence of events regarding the cardiac cycle?
multiple choice
isovolumic contraction, isovolumic relaxation, ejection, passive ventricular filling, active ventricular filling
isovolumic relaxation, isovolumic contraction, ejection, passive ventricular filling, active ventricular filling
isovolumic contraction, ejection, isovolumic relaxation, passive ventricular filling, active ventricular filling
isovolumic contraction, ejection, isovolumic relaxation, active ventricular filling, passive ventricular filling
ejection, isovolumic relaxation, passive ventricular filling, isovolumic contraction, active ventricular filling

Explanation:

The cardiac cycle begins with isovolumic contraction (ventricles contract but no blood is ejected yet). Then comes ejection (blood is pumped out). After that is isovolumic relaxation (ventricles relax with valves closed). Next is passive ventricular filling (blood flows into ventricles passively from atria). Finally, active ventricular filling occurs when atria contract to push more blood into ventricles.

Answer:

Isovolumic contraction, ejection, isovolumic relaxation, passive ventricular filling, active ventricular filling.