In the coronary circuit, the myocardium performs the coordinated contractions that pump blood out of the ventricles. these contractions are the
a. coronary arteries.
b. heart rate.
c. heartbeat.
d. aorta.

C. heartbeat

Explanation:

Myocardium is the muscle of the heart wall. A muscle is a soft structure that supports movement.

Myocardium performs the coordinated contractions that pump blood out of the ventricles and then allows the heart to relax so that the atria can receive blood. These contractions are the heartbeat.

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