PATHOLOGY

Detailed explanation-1: -The one at the top of the esophagus is called the upper esophageal sphincter (UES) and the one at the bottom of the esophagus (which separates the esophagus from the stomach) is called the lower esophageal sphincter (LES).

Detailed explanation-2: -The lower esophageal sphincter is a circular muscle located at the junction of the esophagus and the stomach. Its function is to prevent stomach contents from spilling into the esophagus and mouth.

Detailed explanation-3: -The esophagus extends from the lower border of the cricoid cartilage (at the level of the sixth cervical vertebra) to the cardiac orifice of the stomach at the side of the body of the 11th thoracic vertebra.