On the internal surface of the right atrium, a vertical muscular ridge runs between the openings of the superior and inferior vena cava. Which external feature of the atrium corresponds to this ridge?

• A Sinuatrial nodal artery groove
• B Coronary sulcus
• C Anterior interventricular sulcus
• D Sulcus terminalis ✓

Explanation

The crista terminalis is the smooth muscular ridge inside the right atrium separating the smooth-walled sinus venarum posteriorly from the rough pectinate muscles of the auricle anteriorly. Externally it corresponds to a shallow groove called the sulcus terminalis, which also marks the site where the sinoatrial node sits subepicardially. The coronary and interventricular sulci are grooves between chambers, not counterparts of the crista terminalis.

Reference: Gray's Anatomy for Students, 4th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.