Where do the coronary arteries begin?

Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.

Illustration of a human heart cross-section showing four chambers-left and right atria and ventricles-with labeled major blood vessels. An inset highlights cardiac muscle tissue, showing myocytes and intercalated disks. — human cardiovascular system The human heart is both a pump and a muscle. Its four chambers move blood efficiently, while cardiac muscle cells joined by intercalated disks synchronize each contraction.

The coronary arteries originate from the right and left aortic sinuses (also known as the sinuses of Valsalva), which are small bulges located at the base of the ascending aorta just beyond, or distal to, the aortic valve.1

Specifically, the opening (or ostium) of the right coronary artery is situated in the right aortic sinus, while the opening of the left coronary artery is located in the left aortic sinus, positioned just above the aortic valve ring. These vessels serve as the first branches of the aorta, ensuring that oxygen-rich blood is delivered directly to the heart muscle.1234