Answer:
Coronary sinus
Step-by-step explanation:
The coronary sinus has a length of 15 to 65 mm and they are found in the posterior part of the coronary sulcus which is located on the posterior surface of heart. It acts as a primary collector of cardiac blood and then drains the blood into the right atrium. The cardiac blood is received from ventricular veins and the oblique vein of the left atrium.