In an adult the dural sac terminates caudally at S2. The termination of the adult spinal cord, on the other hand, is at L1-2 and is called the conus medullaris.
In newborns the dura mater ends at S3, and the conus medullaris at L3. This changes over the first year of life.
Spinal Anatomy (Adults)
- Dural Sac: S2
- Spinal cord: L2 (conus medullaris)
Spinal Anatomy (Newborns)
- Dural Sac: S3
- Spinal cord: L3 (conus medullaris)