Question

How does myelin aid propagation of an action potential along an axon? How do the nodes of Ranvier help this process?

Short answer

Myelin stops the axon's current from leaking out. At precise locations along the axon, nodes of Ranvier allow the action potential to renew.

Step-by-step solution

Introduction

The axons of nerves are protected by myelin sheaths. These sheaths are an extension of the plasma membrane made of lipids that are produced by Schwann cells in the peripheral nervous system and oligodendrocytes in the central nervous system. The nodes of Ranvier, specific areas that are required for the transmission of an action potential along the axon, routinely interrupt the myelin sheath along the length of the axon. Changes in size or function have the potential to compromise a neuron's effectiveness, contributing to the emergence of neurological illnesses. The nodes of Ranvier are crucial for the speed and timing of impulse transport from one neuron to another.

The explanation 

Myelin stops the axon's current from leaking out. At precise locations along the axon, nodes of Ranvier allow the action potential to renew. They also help the cell conserve energy because they prevent the requirement for sodium-potassium transporters and voltage-gated ion channels along myelinated axonal sections.