part of part of existence ends during fully formed stage anatomical system digestive system alimentary part of gastrointestinal system All metazoans (with degenerate exceptions) have some sort of digestive cavity with a means of entrance to and exit from it.[well established][VHOG] BTO:0000058 CALOHA:TS-0407 EHDAA2:0000110 EHDAA:514 EMAPA:16246 EV:0100056 FMA:71132 GAID:294 GI tract MA:0000323 MESH:A03.492 The part of the digestive system that excludes the hepatobiliary system. The system that includes the esophagus, stomach, small and large intestine, anus, liver, biliary tract, and pancreas[ncithesaurus:Gastrointestinal_System]. UBERON:0005409 UMLS:C0012240 VHOG:0000412 alimentary system alimentary tract galen:GastrointestinalTract gastro-intestinal system gastrointestinal (GI) tract gastrointestinal system gastrointestinal tract that many anatomy ontologies consider this synonymous with digestive system. here we follow MA in dividing digestive system into gastrointestinal and hepatobiliary. hepatobiliary includes the liver and biliary tract. species-specific AO classes are categorized according to whether liver is included. For example, XAO includes liver as part of XAO:0000125 alimentary system, so we assume this class is the more generic class. We have one entity that is part of both gastrointestinal and hepatobiliary systems: hepatopancreatic ampulla. the decision to split digestive and gastrointestinal in this way may be revisited. As it currently stands, this class more closely aligns what MA calls the alimentary system uberon