<Tr> <Th_colspan="2"> Identifiers </Th> </Tr> <Tr> <Th> FMA </Th> <Td> 67498 </Td> </Tr> <Tr> <Td_colspan="2"> Anatomical terminology (edit on Wikidata) </Td> </Tr> <P> In biology, an organ or viscus is a collection of tissues joined in a structural unit to serve a common function . In anatomy, a viscus is an internal organ, and viscera is the plural form . </P>

At which level of structural organization is the bladder