Upper esophageal sphincter

Upper Esophageal Sphincter

The Upper Esophageal Sphincter (UES) is a region of the esophagus that is responsible for preventing air from entering the esophagus and food from refluxing into the pharynx. It is located at the top of the esophagus and is one of two sphincters, the other being the Lower Esophageal Sphincter (LES).

Anatomy

The UES is composed of a combination of skeletal muscle, similar to the esophagus, and is under voluntary control. It is approximately 2-3 cm in length and is located at the level of the cricoid cartilage.

Function

The primary function of the UES is to prevent the reflux of food and secretions from the esophagus back into the pharynx. It also prevents air from entering the esophagus during respiration. The UES remains in a state of contraction, or closure, except during swallowing, belching, and vomiting.

Clinical Significance

Dysfunction of the UES can lead to a variety of medical conditions, including Gastroesophageal Reflux Disease (GERD), Laryngopharyngeal Reflux (LPR), and Dysphagia. These conditions can cause symptoms such as heartburn, regurgitation, and difficulty swallowing.

See Also

• Esophagus
• Lower Esophageal Sphincter
• Gastroesophageal Reflux Disease
• Laryngopharyngeal Reflux
• Dysphagia

References

Upper esophageal sphincter Resources
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