Myelin sheath is absent in:-
Myelin sheath is absent at following sites:- 1) Nodes of Ranvier 2) Proximal pa of Axon (Pre axon) 3) Near the termination of Axon. 4) At the clefts of Schmidt- Lantermann.
Pre-axon
Axons of CNS
Optic nerve.
Motor roots.
Introduction to Central Nervous System