| Namespace | MPheno.ontology | Obsolete | false |
| description | any structural anomaly of the middle layer of the muscularis; it is continuous with the circular layer of the esophagus, but is absent in the fundus and lies concentric to the longitudinal axis of the stomach; the circular layer is normally tonically constricted forming a functional pyloric sphincter, which controls the movement of chyme into the duodenum |
