Coronary arteries

The heart pumps blood to the lungs and around the body, but its muscle cells also need a supply of oxygen and glucose. They receive these through the coronary arteries, blood vessels that run over the heart. Oxygen enables the muscle cells to release energy by respiration so that the heart can keep contracting.

The coronary arteries deliver oxygenated blood to the heart muscle; blood passing through the heart’s chambers alone does not supply all of that muscle directly.