In a healthy adult, the spinal cord (conus medullaris) terminates at which vertebral level?

• A Lower border of T12
• B Lower border of L1 ✓
• C Lower border of L3
• D S2 vertebral level

Explanation

The conus medullaris ends at the lower border of L1, or at the L1-L2 disc space, in adults. Lumbar puncture is therefore performed at the L3-L4 or L4-L5 interspace, well below the cord, among the cauda equina roots. The L3 level applies to the newborn; the cord ascends during growth because the vertebral column elongates faster than the cord. S2 marks the lower end of the dural sac.

Reference: Gray's Anatomy, 42nd ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.