In a normal heart, which of the following veins empties into the coronary sinus?

The correct answer is that all of the veins listed — the Great Cardiac Vein, Small Cardiac Vein, and Middle Cardiac Vein — do indeed drain into the coronary sinus.

The coronary sinus is a large vessel located on the posterior aspect of the heart, responsible for collecting deoxygenated blood from the myocardium (heart muscle) and returning it to the right atrium. Each of the veins mentioned plays a vital role in this process:

1. The Great Cardiac Vein, which runs along the anterior interventricular sulcus, drains blood from the anterior parts of the heart, particularly from the left ventricle, the interventricular septum, and parts of the left atrium.

2. The Middle Cardiac Vein, located in the posterior interventricular sulcus, primarily drains the area supplied by the posterior interventricular artery, including the right ventricle and parts of the left ventricle.

3. The Small Cardiac Vein generally collects blood from the right atrium and right ventricle and follows the path of the right coronary artery before draining into the coronary sinus.

The coordinated drainage of these veins into the coronary sinus is essential for the effective management of the heart's