The ostium, or opening, of the right coronary artery is in the right aortic sinus and that of the left coronary artery is in the left aortic sinus, just above the aortic valve ring.

What is an ostium in the heart?

An ostium (pl. ostia) is a generic medical term for "hole" - for example, there are coronary ostia in the aorta through which blood flows to the coronary arteries. Most people are born with two coronary ostia, one each for the left coronary artery and the right coronary artery.

What is the ostium in anatomy?

An ostium (plural ostia) in anatomy is a small opening or orifice.