Which feature distinguishes the optic nerve from other peripheral nerves?
- A Its axons are myelinated by Schwann cells
- B It is surrounded by extensions of all three meningeal layers, so CSF pressure changes are transmitted to it ✓
- C Its fibers regenerate effectively after transection
- D Its ganglion cell axons synapse before reaching the brain
Correct answer: B. It is surrounded by extensions of all three meningeal layers, so CSF pressure changes are transmitted to it
Explanation
The optic nerve is a CNS tract, not a true peripheral nerve. It is invested by dura, arachnoid and pia mater continuous with those around the brain, so raised intracranial pressure compresses it and produces papilledema. Its axons are myelinated by oligodendrocytes, not Schwann cells, and like other CNS tracts it does not regenerate after transection. Retinal ganglion cell axons run uninterrupted to the lateral geniculate body.
Reference: Snell's Clinical Neuroanatomy, 8th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.