Your heart is a muscle that pumps blood throughout your body.  To do its work, your heart needs a constant supply of oxygen-rich blood which it gets from the lungs.

Coronary arteries are blood vessels that wrap around the heart muscle and keep it supplied with oxygen-rich blood.  When blood is pumped by the left ventricle, it is forced into the body’s largest artery, the aorta, located at the top of the heart.  Two coronary arteries, the left main artery and the right coronary artery, branch off the aorta.

The left main artery is about as wide as a drinking straw and less than an inch long.  It branches into two narrower arteries:  the left anterior descending, which travels down the front side of the heart, and the left circumflex, which circles around the left side and then to the back of the heart.  The right coronary artery branches from the aorta, circles around the right side and then to the back of the heart.  They divide into smaller branches, similar to a tree, and go deep into the heart muscle carrying oxygen-rich blood to the cells.