<Tr> <Th> Latin </Th> <Td> vesicula umbilicalis; saccus vitellinus </Td> </Tr> <Tr> <Th> MeSH </Th> <Td> sac A10. 615.284. 981 </Td> </Tr> <Tr> <Th> TE </Th> <Td> E5. 7.1. 0.0. 0.4 </Td> </Tr> <Tr> <Th> FMA </Th> <Td> 87180 </Td> </Tr>

When does the sac turn into a fetus