The coronary blood vessels include both arteries and veins, according to the Cleveland Clinic. As stated by Stanford Hospital, coronary arteries supply oxygen-rich blood to the muscle of the heart. The Cleveland Clinic states that coronary veins return deoxygenated blood to the right atrium of the heart.
Stanford Hospital states that the heart depends on a constant supply of oxygenated blood to function properly. The first arteries to extend off the aorta are the two main coronary arteries, called the left and right coronary arteries, as stated by About.com. The aorta is the largest artery in the human body, supplying blood to all other arteries. Stanford Hospital states the left coronary artery branches into the left anterior descending artery and the circumflex artery, while the right coronary artery divides into the right posterior descending artery and a marginal branch. Smaller branches also diverge from these larger arteries to supply blood to all portions of the heart muscle.
Blockages in any of the coronary arteries lead to an interruption in blood flow to the heart and can have serious consequences. Stanford Hospital explains that this reduction in the supply of oxygen and nutrients sometimes leads to heart attack or even death.