part of part of has part has part has developmental contribution from organism subdivision proctodeum anal region Although all vertebrates have a digestive tract and accessory glands, various parts of this system are not necessarily homologous, analogous, or even present in all species. Therefore, broad comparisons can be best made under the listings of headgut, foregut, midgut, pancreas and biliary system, hindgut.[uncertain][VHOG] EFO:0000847 EHDAA2:0000122 EHDAA:2931 EMAPA:16831 MA:0000329 MAT:0000042 MIAA:0000042 The anus and surrounding regions. Encompasses both internal and external regions, where present UBERON:0001353 UMLS:C0230120 VHOG:0000395 WBbt:0006919 posterior posterior end of organism uberon terminal part of digestive tract