What does the small cardiac vein return blood from?

• A. Left ventricle
• B. Right ventricle
• C. Both atria
• D. Both ventricles

Answer: (B)

The small cardiac vein primarily returns blood from the right ventricle, as well as some areas of the right atrium and the right side of the interventricular septum. It is notable for accompanying the right coronary artery and draining into the coronary sinus, which then empties into the right atrium.

This is key in understanding the overall venous drainage system of the heart. The small cardiac vein is part of the coronary venous system that helps maintain the heart's functionality by transporting deoxygenated blood away from the myocardium. Being specifically associated with the right side of the heart highlights its role in the cardiac cycle, especially concerning the functioning of the right ventricle, which is responsible for pumping deoxygenated blood to the lungs.