coronary sinus

The coronary sinus is a venous channel that collects most of the blood from the heart's walls and empties it into the right atrium. It is continuous with the largest of the cardiac veins and is derived from the sinus venosus. Several coronary veins drain the heart's tissues and empty into the coronary sinus. The heart has its own vascular system, the coronary arterial system, which supplies it with oxygen and nourishment, as it cannot rely solely on the blood within its chambers. Venous blood from the heart is carried by cardiac veins that typically follow the path of the arteries and converge to form the coronary venous sinus.123