part_of part of part of anatomical structure multicellular organism anal region http://upload.wikimedia.org/wikipedia/commons/f/fb/Gray408.png https://github.com/obophenotype/uberon/issues/507 MIAA:0000042 posterior posterior end of organism UMLS:C0230120 EFO:0000847 EHDAA:2931 UBERON:0001353 WBbt:0006919 VHOG:0000395 EMAPA:16831 MA:0000329 NCIT:C32069 EHDAA2:0000122 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] SCTID:362680001 The anus and surrounding regions. Encompasses both internal and external regions, where present. MAT:0000042