#anatomical_sphincter__sphincter__sphinctermuscle  a ring of muscle that contracts to close an opening
  supertype:  muscle__musculus  one of the contractile organs of the body
  subtype:  physiological_sphincter__physiologicalsphincter  a sphincter that is not recognizable at autopsy because its resting arrangement cannot be distinguished from adjacent tissue
     subtype:  cardiac_sphincter__cardiacsphincter  the valve between the distal end of the esophagus and the stomach; the physiological sphincter at the esophagogastric junction
  subtype:  anal_sphincter__sphincter_ani__sphincterani__musculus_sphincter_ani  the sphincter muscle of the anus
  subtype:  urethral_sphincter__musculus_sphincter_urethrae  a striated sphincter muscle that constricts the urethra
  subtype:  bladder_sphincter__bladdersphincter__musculus_sphincter_vesicae  the sphincter muscle of the urinary bladder; made up of a thickened muscular layer of bladder around the urethral opening
  subtype:  musculus_sphincter_ductus_choledochi  the smooth muscle sphincter of the common bile duct
  subtype:  musculus_sphincter_ductus_pancreatici  the smooth muscle sphincter of the main pancreatic duct
  subtype:  pupillary_sphincter__pupillarysphincter__musculus_sphincter_pupillae  a ring of smooth muscle surrounding the iris
  subtype:  pyloric_sphincter__pyloricsphincter__pyloric_valve__pyloricvalve__musculus_sphincter_pylori  the sphincter muscle of the pylorus that separates the stomach from the duodenum

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