Medullated Nerve / Myelinated Fibre:
1. The axon is surrounded by a layer of fatty proteinaceous materials called myelin sheath.
2. The myelin sheath provides white colour to the nerve fibre.
3. Presence of nodes of Ranveir.
4. The conduction of nerve impulse is faster.
5. They are found in brain and spinal chord.
Non-Medullated Nerve / Non-Myelinated Fibre:
1. Myelin sheaths are absent.
2. It appears grey in colour due to absent of myelin sheath.
3. Nodes of Ranveir are absent.
4. The conduction of nerve impulse is slower.
5. These are found in sympatric and para-sympathetic nerves.