What is the primary function of the myelin sheath in the nervous system?

The primary function of the myelin sheath in the nervous system is to insulate nerve fibers and increase the speed of electrical signals transmitted along these fibers. Myelin is a fatty substance that wraps around the axons of neurons, creating a protective layer. This insulation allows for quicker electrical impulses through a process known as saltatory conduction, where the nerve signal jumps between the gaps (Nodes of Ranvier) in the myelin sheath rather than traveling continuously along the entire length of the axon.

This increased speed is vital for efficient communication between neurons, facilitating rapid responses and coordination throughout the nervous system. For example, in individuals with multiple sclerosis, where myelin is damaged, signal transmission slows down significantly, leading to various neurological symptoms. Understanding the function of the myelin sheath highlights its importance in ensuring fast and effective nerve function.