The<unk>  supply oxygenated blood to the heart muscle itself.  Although blood fills the chambers of the heart, the muscle tissue of the heart, or myocardium, is so thick that it requires coronary blood vessels to deliver blood deep into it.  There are two primary<unk>  supplying the heart, the left coronary artery and the right coronary artery.  These two epicardial<unk>  course along the surface of the heart and this is why they are called "epicardial" (on top of the heart)<unk> .  Smaller<unk>  dive deep into the heart muscle and are called subendocardial<unk> .  The cardiac veins are the vessels that remove the deoxygenated blood from the heart muscle and return it to the right atrium.
Coronary arteries
Cardiac veins
Thoracic aorta
Pulmonary circulation
Coronary circulation
Pulmonary valve
Coronary sinus
Arterial tree