Question Detail
Question
Blood moves from the atria into the ventricles when:
Correct Answer
Option B is the correct answer.
Detailed Explanation
Blood moves from the atria into the ventricles when the atria contract (atrial systole). This contraction forces additional blood into the ventricles, completing ventricular filling before ventricular contraction begins.
Hint
The contraction of the upper chambers pushes blood into the lower chambers.