How does a myelin sheath affect nerve impulses?

Answer 1

Myelin sheath does several things that affect the speed of an action potential.

1. It acts as an insulator around a neuron axon, thereby focusing the propagation of the action potential along the axis of the axon.

2. The action potential "leaps" from one node of Ranvier (the node in between two myelinated segments) to the next, and to the next, and to the next, and so on, faster than the action potential can propagate as a wave along an unmyelinated axon of the same diameter.

3. The regions along a myelinated axon depolarize locally and successively, thus allowing an action potential to travel along an axon using less energy, which in turn allows the neuron to repolarize more quickly, and thus be ready to conduct the next action potential sooner, thereby increasing the overall speed of information transmission.

Answer 2

A myelin sheath acts as an insulating layer around nerve fibers, which helps to increase the speed at which nerve impulses can travel along the neuron. This is because the myelin sheath allows for a process called saltatory conduction, where the nerve impulse "jumps" between gaps in the myelin sheath called nodes of Ranvier, rather than traveling continuously along the entire length of the nerve fiber.

Answer 3

There is gap between the myelin sheath. This speeds up the conduction across the axons. This is called as saltatory conduction.