Final answer:
The coronary arteries branch off from the aorta to supply the heart with blood. There are two main coronary arteries: the left arises from the left posterior aortic sinus, and the right from the anterior aortic sinus.
Step-by-step explanation:
The coronary arteries, which supply blood to the myocardium and other components of the heart, branch off from the aorta. Specifically, they arise from two of the three dilations, or sinuses, located in the wall of the aorta just superior to the aortic semilunar valve. The left coronary artery stems from the left posterior aortic sinus, while the right coronary artery originates from the anterior aortic sinus. The coronary arteries encircle the heart like a crown and are crucial for delivering oxygenated blood to the heart muscle.