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

The system that includes the esophagus, stomach, small and large intestine, anus, liver, biliary tract, and pancreas[ncithesaurus:Gastrointestinal_System].

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.

uberon

gastrointestinal (GI) tract, alimentary tract, gastro-intestinal system, gastrointestinal tract, alimentary system, gastrointestinal system, gastroenterological system, GI tract

All metazoans (with degenerate exceptions) have some sort of digestive cavity with a means of entrance to and exit from it.[well established][VHOG]

UBERON:0005409

• gastrointestinal sphincter
• lower digestive tract
• gastrointestinal system mucosa
• gastrointestinal system serosa
• gastrointestinal system epithelium
• gastrointestinal system smooth muscle
• food storage organ
• intestine