Variación en la motilidad del esfínter esofágico superior durante la inducción anestésica

Abstract

Upper esophageal sphincter (UES) is a high pressure zone located at the bottom of the pharynx and protects the airway from the entrance of esophageal content. It is constituted by the inferior constrictor muscle of the pharynx (which is composed of thyropharyngeal and cricopharyngeal muscles) and cervical esophagus. UES consists on striated muscle fibers distributed in two zones: rapid twich oblique fibers correspondent to tyropharyngeal muscle and rapid but mostly slow twich horizontal fibers belonging to cricopharyngeal muscle. This permits UES maintain a constant basal tone and respond quickly to reflexes. Supratentorial and infratentorial areas are implicated in swallowing process and influence on upper esophageal sphincter motility...