A coin is struck at 25 cm from incisor in the esophagus, this place coincides with-

Esophagus shows three normal constriction which are narrower portions of esophagus and foreign body can be held there. These constrictions are : - At pharyngo-esophageal junction (C6) - 15 cm from the upper incisors. At crossing of arch of aorta and left main bronchus (T4) - 25 cm from upper incisors. Where it pierces the diaphragm (T10) - 40 cm from upper incisors.