Question

multiple choice question
when the ____ contract, blood is forced into the ____ through the open av valves.
o ventricles; atria
o atria; ventricles
o ventricles; aorta
o atria; pulmonary trunk

Explanation:

During the cardiac cycle, when the atria contract (atrial systole), the atrioventricular (AV) valves are open, and blood is forced from the atria into the ventricles.

Answer:

B. atria; ventricles