<span>The coronary sinus is the venous structure that does not empty blood into the right atrium. The coronary sinus is a collection of veins joined together to form a large vessel that collects blood from the heart muscle (myocardium). </span><span>It receives blood mainly from the small, middle, great and oblique cardiac <span>veins</span></span>. It also receives blood from the left marginal vein and the left posterior ventricular vein.
