Question

Conduction of nerve impulse in myelinated and non Myelinated nerve fibres?
Short note on both

Answer 1

The main purpose of myelin is to increase the speed at which electrical impulses propagate along the myelinated fiber.
Myelinated fibers form the bulk of the somatic nerves.
Structurally, they are made up of following parts from within outwards.



In unmyelinated fibers, electrical impulses (action potentials) travel as continuous waves, but, in myelinated fibers, they "hop" or propagate by saltatory conduction.
Non-myelinated fibers comprise the smaller axons of the CNS, in addition to peripheral postganglionic autonomic fibers, several types of fine sensory fibers (C fibers of skin, muscle and viscera), olfactory nerves, etc.
Structurally, a non-myelinated fiber consists of a group of small axons that have invaginated separately a single Schwann cell (in series) without any spiraling of the mesaxon.