The cardiac muscle
A) extracts oxygen and nutrients from the blood within its chambers.
B) receives its blood supply primarily during ventricular systole when blood is forced into the vessels supplying the heart.
C) receives its blood supply as the blood returning to the heart from the lung passes through the cardiac circulation before being pumped to the systemic circulation.
D) receives most of its blood supply during ventricular diastole by means of the coronary circulation.
E) none of these answers.

Question

Quizplus · Accepted Answer

The cardiac muscle receives most of its blood supply during ventricular diastole by means of the coronary circulation. During ventricular diastole, the coronary arteries are perfused with blood, which supplies the heart muscle with oxygen and nutrients. During ventricular systole, the coronary arteries may be compressed by the contracting ventricles, limiting blood flow to the heart.

The Cardiac Muscle