Coronary circulation

Heart tissue is supplied with blood by the coronary circulation.

The right and left coronary arteries branch from the aorta close to where it emerges from the heart.

These vessels then branch extensively to supply the whole of the myocardium.

Most of the blood flow occurs when the heart muscle is relaxed, since contractions almost totally occlude these vessels.

Most of the cardiac veins drain into the coronary sinus a large vein which empties into the right atrium.