Which of the following concerning the heartbeat is true?
A) Only the ventricles contract in unison.
B) Only the atria contract in unison.
C) The atria contract together in unison, and the ventricles contract in unison.
D) Only the atrium and ventricle on the right side of the heart contract in unison.
E) Only the atrium and ventricle on the left side of the heart contract in unison.

Question

Quizplus · Accepted Answer

The correct answer is C because the atria contract together in unison to fill the ventricles with blood before the ventricles contract together in unison to pump blood out of the heart. Both sides of the heart (left and right) contract in unison.

Which of the Following Concerning the Heartbeat Is True