Anatomy and function of the heart.
The heart is a muscle and like all muscles it requires blood to supply it oxygen in order to function properly. Because the heart can never rest, it requires special arteries to supply its blood. These arteries are known as coronary arteries and supply oxygen rich blood specifically to the heart. The first of the two major coronary arteries is the left main coronary artery (LMCA) which quickly divides into the left anterior descending (LAD) and the left circumflex (LCx), and the second is right coronary artery (RCA). Each of these arteries has several branches which supply blood to discrete areas of the heart.