What is coronary circulation?

• A. Circulation supplying the heart muscle via the coronary arteries
• B. Circulation of blood to the brain
• C. Blood flow through the limbs
• D. Circulation of blood through the lungs

Answer: (A)

Coronary circulation is the network that provides blood to the heart muscle itself. The heart needs its own dedicated blood supply, so the aorta gives rise to coronary arteries that wrap around and feed the myocardium with oxygen-rich blood. Blood returns from the heart muscle through the coronary veins into the coronary sinus, draining into the right atrium. Perfusion of the heart tissue mainly occurs during diastole, when the heart is relaxed and the coronary vessels are less compressed.

This is different from the circulation that supplies the brain or limbs, and from the circulation that moves blood to and from the lungs. The brain and limbs receive systemic arterial blood via other large vessels, while the lungs are served by the pulmonary circulation that exchanges gases with air in the lungs.