| Medullated fibre | Non – Medullated fibre |
| 1. Medullary sheath is present around the axon hence also known as Myelinated nerve fibre. | Medullary sheath is absent hence also known as Nonmyelinated nerve fibre. |
| 2. They have nodes of Ranvier at regular intervals. | They do not have nodes of Ranvier. |
| 3. Saltatory conduction takes place in medullated nerve fibres. | Saltatory conduction is not seen in nonmedullated nerve fibre. |
| 4. These nerve fibres conduct the nerve impulse faster. | These nerve fibres conduct nerve impulse at slow rate. |
| 5. These fibres appear white in colour due to an insulating fatty layer (myelin sheath). | These fibres appear grey in colour due to absence of fatty layer. |
| 6. Schwann cell of this nerve fibre secrete myelin sheath. | Schwann cell of this nerve fibre does not secrete myelin sheath. |
| 7. Cranial nerves of vertebrates are medullated. | Nerves of autonomous nervous system are non |
