<Table> <Tr> <Th_colspan="2"> Inferior vena cava </Th> </Tr> <Tr> <Td_colspan="2"> </Td> </Tr> <Tr> <Td_colspan="2"> Superior vena cava, inferior vena cava, azygos vein and their tributaries </Td> </Tr> <Tr> <Th_colspan="2"> Details </Th> </Tr> <Tr> <Th> Source </Th> <Td> common iliac vein lumbar veins testicular vein renal vein suprarenal vein hepatic vein </Td> </Tr> <Tr> <Th> Drains to </Th> <Td> right atrium </Td> </Tr> <Tr> <Th> Artery </Th> <Td> abdominal aorta </Td> </Tr> <Tr> <Th_colspan="2"> Identifiers </Th> </Tr> <Tr> <Th> Latin </Th> <Td> vena cava inferior </Td> </Tr> <Tr> <Th> MeSH </Th> <Td> A07. 231.908. 949.648 </Td> </Tr> <Tr> <Th> TA </Th> <Td> A12. 3.09. 001 </Td> </Tr> <Tr> <Th> FMA </Th> <Td> 10951 </Td> </Tr> <Tr> <Td_colspan="2"> Anatomical terminology (edit on Wikidata) </Td> </Tr> </Table> <Tr> <Th_colspan="2"> Inferior vena cava </Th> </Tr> <Tr> <Td_colspan="2"> Superior vena cava, inferior vena cava, azygos vein and their tributaries </Td> </Tr> <Tr> <Th_colspan="2"> Details </Th> </Tr>

What system is the vena cava part of