In a normal adult examined by MRI, the caudal end of the spinal cord lies at which vertebral level?
- A Lower border of T12
- B Lower border of the third lumbar vertebra
- C Lower border of the first lumbar vertebra, near the L1-L2 intervertebral disc ✓
- D Level of the sacral hiatus
Correct answer: C. Lower border of the first lumbar vertebra, near the L1-L2 intervertebral disc
Explanation
The conus medullaris ends at the L1-L2 disc level in adults, which is why lumbar puncture is performed at L3-L4 or below. Option B is the level found in the newborn, where the cord initially extends to about L3 before the vertebral column outgrows the cord. Option D marks the caudal end of the dural sac, not the cord.
Reference: Snell's Clinical Neuroanatomy, 8th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.