This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Thorax, Subject name: Anatomy
Cista terminalis is present in 
Select and explain. 
A. Right Atrium, B. Left Atrium, C. Right Ventricle, D. Left Ventricle
A: Right Atrium
Answer: A: Right Atrium 
Explanation: Cista Terminalis is present in the right atrium. It is a muscular ridge that runs anteriorly along the atrial wall from the opening of the superior vena cava. It corresponds externally to Sulcus terminalis. It is the site of origin of pectinate muscles. It divides the right atrium into a smooth posterior pa and a rough anterior pa. Both the vena cavae empty into the posterior smooth pa. Ref: Gray&;s Anatomy 41st edition. Pgno: 1000