The myocardium receives its blood supply directly from the (a) aorta, (b) coronary arteries, (c) coronary sinus, (d) pulmonary arteries.
The Correct Answer and Explanation is:
The correct answer is (b) coronary arteries.
The myocardium, which is the muscle layer of the heart, receives its blood supply from the coronary arteries. These arteries are vital for delivering oxygen-rich blood to the heart muscle to meet its metabolic demands. There are two main coronary arteries—the left and right coronary arteries—which branch off from the aorta, just above the aortic valve.
The left coronary artery typically divides into two branches: the left anterior descending artery (LAD) and the circumflex artery. The right coronary artery supplies the right side of the heart. These arteries run along the surface of the heart and penetrate into the myocardium, ensuring that every part of the heart muscle is adequately nourished.
The coronary sinus, mentioned as option (c), is a large vein that collects deoxygenated blood from the myocardium. It drains into the right atrium but does not supply blood to the heart muscle itself.
The aorta, listed as option (a), is the main artery that carries oxygenated blood from the left ventricle to the body, but it does not directly supply blood to the myocardium. Instead, it gives rise to the coronary arteries.
The pulmonary arteries, option (d), carry deoxygenated blood from the right ventricle to the lungs for oxygenation, not to the myocardium.
In summary, the coronary arteries are specifically responsible for supplying oxygen-rich blood to the myocardium, allowing the heart to function effectively. Without this blood supply, the heart muscle would become deprived of oxygen, potentially leading to serious conditions like angina or myocardial infarction (heart attack).
