Lower Esophageal Sphincter

Lower Esophageal Sphincter (LES). The valve that is located at the bottom of the esophagus where it is connected to the stomach. Improper function of the LES can cause acid reflux.


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Esophageal Sphincter, Lower: The physiologic or functional barrier to Gastroesophageal Reflux at the esophagogastric junction. Sphincteric muscles remain tonically contracted during the resting state and form the high-pressure zone separating the lumen of the Esophagus from that of the Stomach. (Haubrich et al, Bockus Gastroenterology, 5th ed., pp399, 415)2

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Lower Esophageal Sphincter: A group of muscles between the esophagus and stomach that actively prevents food from rising up out of the stomach.3

Categories for Lower Esophageal Sphincter

Category of Lower Esophageal Sphincter:

  • Gastrointestinal Sphincter

Anatomy Articles

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Disease and Condition Articles

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  1. Source: RDCRN (NCATS/NIH): rarediseasesnetwork.org/ cms/ cegir/ Learn-More/ Glossary
  2. Source: MeSH (U.S. National Library of Medicine)
  3. Source: NCI Thesaurus
  4. ibid.
  5. Source: NIDDK (NIH): niddk.nih.gov/ health-information/ health-topics/ digestive-diseases/ ger-and-gerd-in-adults/ Pages/ overview.aspx

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