sphincter

Introduction

A specialized ring of muscle that surrounds an orifice. Contractions of the sphincter musculature partially or completely close the orifice.

More general terms

• anatomic structure

More specific terms

• anal sphincter
• lower esophageal sphincter (LES)
• pyloric sphincter
• sphincter of Oddi; sphincter of the hepatopancreatic/bilaropancreatic ampulla; Glisson sphincter
• sphincter pupillae
• urethrovaginal sphincter