Subarachnoid space extends up to:
Ans. D Lower border of S2Ref: Netter's Clinical Anatomy, 3rd ed. pg. 420* The subarachnoid space extends up to lower border of S2 where the dura fuses with filum terminale and obliterates the subarachnoid space.* The spinal cord extends from upper border of atlas to lower border of L1 or upper border of L2. The spinal cord ends in a sharp tip called conus medullaris.* The conus is continuous with filum terminale, which is a fine connective tissue element which descends up to the dorsum of the first coccygeal ligament.
Lower border L1
Upper border L1
Upper border of S2
Lower border of S2
Neuroanatomy