The cardiac cycle has two phases:
A) diastole in which the ventricles contract, and systole in which the ventricles relax.
B) systole in which the ventricles contract, and diastole in which the ventricles relax.
C) systole in which the atria contract, and diastole in which the ventricles contract.
D) diastole in which the atria relax, and systole in which the ventricles relax.
E) systole in which the atria relax, and diastole in which the atria contract.

Question

Quizplus · Accepted Answer

During systole, the ventricles contract and pump blood out of the heart, while during diastole, the ventricles relax and fill with blood. Therefore, option B is the correct answer. The other choices include incorrect descriptions of the phases of the cardiac cycle.

The Cardiac Cycle Has Two Phases