Blood vessels supplying oxygenated blood to the heart are known as coronary arteries. The two important coronary arteries are the right coronary artery (RCA) and the left main coronary artery (LMCA). Left main coronary artery has two branches – left circumflex coronary artery (LCX) and left anterior descending coronary artery (LAD). Each of these give several branches to supply the heart muscle. Both the left and right coronary arteries arise from the root of the aorta, the biggest blood vessel arising from the heart, carrying blood to the whole body.
Blood returning from the heart, containing deoxygenated blood are known as coronary veins. The biggest coronary vein is the coronary sinus (CS), which drains into the right atrium, the upper right chamber of the heart.