Which artery primarily supplies the heart muscle on the left side?

• A. Left Coronary Artery
• B. Right Coronary Artery
• C. Circumflex Artery
• D. Left Subclavian Artery

Answer: (A)

The left coronary artery is the main supplier of blood to the left side of the heart. It arises from the left aortic sinus and splits into the left anterior descending artery and the circumflex artery. The left anterior descending runs along the front of the heart, nourishing the anterior wall of the left ventricle and much of the interventricular septum. The circumflex travels in the atrioventricular groove to feed the left atrium and the lateral/posterior aspects of the left ventricle. While the right coronary artery mainly serves the right heart, the left coronary artery provides the primary oxygenated blood for the left-sided cardiac muscle. The left subclavian artery, on the other hand, does not supply the heart.