Like all organs, your heart is made of tissue that requires a supply of oxygen and nutrients. Although its chambers are full of blood, the heart receives no nourishment from this blood. The heart receives its own supply of blood from a network of arteries, called the coronary arteries. Two major coronary arteries branch off from the aorta near the point where the aorta and the left ventricle meet: 1  Right coronary artery supplies the right atrium and right ventricle with blood. 2  Left main coronary artery branches into the circumflex artery and the left anterior descending artery.