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lower oesophageal sphincter
medical dictionary

<anatomy> A muscular sphincter located at the junction of the oesophagus and the stomach. On closure the lower oesophageal sphincter prevents the back wash (reflux) of stomach acid into the oesophagus where it may damage the mucosa.

See: gastro-oesophageal reflux disease.

American spelling: lower esophageal sphincter

(16 Mar 1998)