Distance of the Lower Esophageal Sphincter from the upper incisors is -: (A) 15cm, (B) 22.5cm, (C) 27.5cm, (D) 37.5cm
Answer is D. There are 4 esophageal constrictions. They are at 15cms, 22.5cms, 27.5cms and 37.5 to 40 cms, from the incisors. The fourth constriction is when the esophagus pierces the diaphragm, and here the lower esophageal sphincter is there.