Filum terminale
NervousOrgansWhole body
- What it is
- A thin thread of pia mater running from the tip of the conus medullaris down through the dural sac (internal part) and, wrapped in dura, on to the back of the coccyx (external part).
- Function
- Anchors the lower end of the spinal cord and steadies it within the vertebral canal.
- Size
- About 20 cm long and 1 mm thick
- Clinical note
- A short, thick filum (tethered cord) pulls on the conus as a child grows, causing back pain, leg weakness and bladder problems; it is treated by cutting the filum.