The coronary sinus is best described as which of the following?

The coronary sinus is best described as which of the following?

• A. A large vein that drains coronary veins into the right atrium
• B. An artery that supplies the heart muscle
• C. A chamber of the heart
• D. A valve between atria and ventricles

Answer: (A)

The coronary sinus is a large venous channel that collects deoxygenated blood from the heart’s own veins and drains it into the right atrium. It sits in the posterior part of the coronary sulcus and receives blood from the major cardiac veins, then empties into the right atrium near the superior or inferior vena cava openings. This makes it the main pathway for returning myocardial blood to the heart before it re-enters the circulation. This contrasts with arteries, which deliver oxygenated blood to the heart muscle, and with chambers or valves, which are parts of the heart’s cavities and flow-regulating structures. So describing the coronary sinus as a large vein that drains coronary veins into the right atrium fits its actual role and location.

The coronary sinus is a large venous channel that collects deoxygenated blood from the heart’s own veins and drains it into the right atrium. It sits in the posterior part of the coronary sulcus and receives blood from the major cardiac veins, then empties into the right atrium near the superior or inferior vena cava openings. This makes it the main pathway for returning myocardial blood to the heart before it re-enters the circulation.

This contrasts with arteries, which deliver oxygenated blood to the heart muscle, and with chambers or valves, which are parts of the heart’s cavities and flow-regulating structures. So describing the coronary sinus as a large vein that drains coronary veins into the right atrium fits its actual role and location.