Related Experiment Video
Updated: Apr 28, 2026

Robotic Myotomy and Partial Fundoplication for Achalasia
Published on: August 11, 2023
[Physiology of the upper esophageal sphincter]
1Klinik und Poliklinik für Phoniatrie und Pädaudiologie, Medizinische Hochschule Hannover, Carl-Neuberg-Str. 1, 30625, Hannover, Deutschland, jungheim.michael@mh-hannover.de.
Abstract:
The upper esophageal sphincter (UES) forms a barrier between the pharynx and the esophagus. When opened, the UES allows the food bolus to pass into the esophagus, as well as permitting emesis and eructation. The basal sphincter tone constitutes a barrier function which serves to prevent reflux and passive aerophagia in the case of deep breathing. Basal sphincter tone is dependent on several influencing factors; during swallowing, sphincter opening and closure follow a complex multiphase pattern. This article presents an overview of the current understanding of UES physiology.
Related Concept Videos
Esophagus
The movement of edibles from the pharynx into the esophagus is facilitated by the upper esophageal sphincter, which is formed primarily by the...
Physiology of the Gastrointestinal System I: Ingestion and Propulsion
Esophageal Achalasia
Gastroesophageal Reflux Disease
Gastroesophageal Reflux Disease I: Meaning and Pathophysiology
Esophageal Strictures-I: Introduction
Etiology
The primary cause of esophageal strictures is long-standing gastroesophageal reflux disease (GERD), accounting for about 70 to 80% of adult cases. Chronic acid reflux can lead to injury and scarring of the esophageal lining, culminating in...

