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What is Constrictions of esophagus when measured from upper incisiors are present at and explain in detail?
The second constriction is at 25 cm from the upper incisor teeth, where it is crossed by the aoic arch and left main bronchus. The third constriction is at 40 cm from the upper incisor teeth, where it pierces the diaphragm; the lower esophageal sphincter (LES) is situated at this level. ref - BDC vol2 , britannica.com