Assertion: pyloric sphincter | /r/HasProperty | a ring of muscle
Facets:
Source sentences:
text: The pyloric sphincter is a ring of muscle that contracts to close the opening between the stomach and the duodenum.
text: The pyloric sphincter, or pylorus, is a ring of muscles that helps to control the passage of food from the stomach into the duodenum (the first part of the small intestine).