The esophagus develops from the cranial portion of the foregut and is recognizable by the third week of gestation.  The esophagus develops into a hollow, highly distensible muscular tube that extends from the epiglottis in the pharynx to the gastroesophageal junction.  In the newborn the esophagus measures 10-11 cm, it grows to a length of about 25 cm in the adult.  Since the esophagus is located within the mediastinum and bound by two sphincters, the pressure within the esophageal lumen is negative compared with the atmosphere.  The esophagus is bound proximally by the upper esophageal sphincter (UES) and distally by the lower esophageal sphincter (LES).  The UES and LES are both physiologic sphincters, meaning that there are no anatomic landmarks that delineate these high pressure regions from the intervening esophageal musculature (1).