Select the best answer or answers from the choices given: 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 :
Correct Answer:
(b) Coronary arteries
Explanation:
The myocardium, the muscular layer of the heart, requires a continuous supply of oxygen and nutrients to function effectively. This blood supply comes directly from the coronary arteries.
The coronary arteries originate from the ascending aorta, just above the aortic valve. As the heart pumps blood, a portion of the oxygen-rich blood is directed into the coronary arteries, ensuring the myocardium remains well-nourished. These arteries branch into smaller arteries and capillaries that penetrate deep into the heart muscle.
Why Other Options Are Incorrect:
- (a) Aorta – The aorta does play a role in supplying blood to the heart, but not directly. The coronary arteries, which arise from the aorta, are the direct suppliers to the myocardium.
- (c) Coronary sinus – The coronary sinus is a large vein that collects deoxygenated blood from the heart muscle and empties it into the right atrium. It does not supply blood to the myocardium.
- (d) Pulmonary arteries – The pulmonary arteries carry deoxygenated blood from the right ventricle to the lungs for oxygenation. They have no role in supplying oxygenated blood to the heart muscle.
Importance of the Coronary Arteries:
Blockage in the coronary arteries can lead to coronary artery disease (CAD), reducing blood flow to the heart muscle and potentially causing myocardial infarction (heart attack). Maintaining good cardiovascular health through diet, exercise, and medical interventions is crucial for keeping the coronary arteries functioning properly.
Now, I will generate an image illustrating the coronary arteries and their role in myocardial blood supply.
Here is an anatomical illustration of the human heart showing the coronary arteries and their role in supplying blood to the myocardium. Let me know if you need any modifications or additional details!