Which vessels are responsible for supplying the myocardium with blood?

The coronary arteries are the vessels responsible for supplying the myocardium, or the heart muscle, with oxygen-rich blood. These arteries branch off from the aorta just above the aortic valve and encircle the heart, providing the necessary blood flow to ensure that the heart muscle can function effectively. Without adequate blood supply from the coronary arteries, the myocardium may suffer from ischemia, which can lead to chest pain (angina) or even a myocardial infarction (heart attack).

The other vessels listed do not serve this primary function. The pulmonary arteries carry deoxygenated blood away from the heart to the lungs for oxygenation, while the aorta distributes oxygenated blood from the heart to the rest of the body. The superior vena cava is responsible for returning deoxygenated blood from the upper body back to the heart. Therefore, the unique role of the coronary arteries in nourishing the heart muscle is what makes them the correct answer in this context.