The<unk>  is the circulation of blood in the blood vessels that supply blood to and from the heart muscle itself.  Although blood fills the chambers of the heart, the muscle tissue of the heart, the myocardium, is so thick that it requires<unk>  blood vessels to deliver blood deep into it.   The<unk>  arteries are the vessels that deliver oxygen-rich blood to the myocardium.  Cardiac veins are the vessels that remove the deoxygenated blood from the heart muscle.   Epicardial<unk>  arteries are the<unk>  arteries that run on the surface of the heart.  These arteries, when healthy, are capable of autoregulation to maintain<unk>  blood flow at levels appropriate to the needs of the heart muscle.  These relatively narrow vessels are commonly affected by atherosclerosis and can become blocked, causing angina or a heart attack.  Subendocardial<unk>  arteries run deep within the myocardium.  The<unk>  arteries are classified as end circulation, since they represent the only source of blood supply to the myocardium: there is very little redundant blood supply, which is why blockage of these vessels can be so critical.
Coronary circulation
Systemic circulation
Cerebral circulation
Pulmonary circulation
Cardiac cycle
Hepatic circulation
Circulatory system
Arterial tree