Small Cardiac Vein
The structure indicated is the small cardiac vein.
The coronary sinus lies posteriorly on the heart in the coronary sulcus and receives four cardiac veins:
- Great cardiac vein
- Middle cardiac vein
- Small cardiac vein
- Posterior cardiac veins
The coronary sinus returns deoxygenated blood to the right atrium of the heart, together with the superior and inferior vena cavae. The small cardiac vein lies in the coronary sulcus between the right atrium and the right ventricle.
Learn more about the blood supply to the heart in this tutorial.