coronary sinus

coronary sinus   n.  A venous sinus that opens into the right atrium of the heart and serves to drain the coronary veins.

Main Entry: coronary sinus
Function: noun
: a venous channel that is derived from the sinus venosus, is continuous with the largest of the cardiac veins, receives most ofthe blood from the walls of the heart, and empties into the right atrium

coronary sinus n.
A short trunk receiving most of the veins of the heart, running in the posterior part of the coronary sulcus and emptying into the right atrium between the inferior vena cava and the atrioventricular orifice.