<Table> <Tr> <Th_colspan="2"> Lumbar puncture </Th> </Tr> <Tr> <Td_colspan="2"> Lumbar puncture in a sitting position . The reddish - brown swirls on the patient's back are tincture of iodine (an antiseptic). </Td> </Tr> <Tr> <Th> ICD - 9 - CM </Th> <Td> 03.31 </Td> </Tr> <Tr> <Th> MeSH </Th> <Td> D013129 </Td> </Tr> <Tr> <Th> eMedicine </Th> <Td> 80773 </Td> </Tr> <Tr> <Td_colspan="2"> (edit on Wikidata) </Td> </Tr> </Table> <Tr> <Th_colspan="2"> Lumbar puncture </Th> </Tr>

Why is csf drawn from l3 and l5