Answer
Sulci are grooves that mark the borders between heart chambers The coronary sulcus marks the boundary betwen the superior atria, and the inferior ventricles.
Work Step by Step
The coronary sulcus is a groove that encircles most of the heart. In life, it contains blood vessels, and is usually partially concealed by fat. It marks the boundary between the atria above, and the ventricles below the groove. The other sulcus on the heart is the interventricular sulcus. This grove marks the border between the right and left ventricles, on the anterior surface of the heart.
