Lower esophageal sphincter lies at what distance from the incisor teeth?
High-Yield Explanation
Ans. is 'c' i.e., 40cm * 2nd constriction is at T4 level where arch of aorta crosses esophagus.Esophageal constrictionsNumberDistance from incisorBony levelAnatomical landmark1st15 cm (6 inches)C6At its beginning (pharyngo-esophageal junction)2nd22.5 cm (9 inches)T4Crossing of aortic arch3rd27.5 cm (11 inches)T6Crossing of left main bronchus4th37.5 - 40 cm (15-16 inches)T10Piercing diaphragm (at lower esophageal sphmotor)