What is the primary role of myelin in the nervous system?

The primary role of myelin in the nervous system is to insulate axons and speed up the transmission of impulses. Myelin is a fatty substance that wraps around the axons of neurons, creating a thick insulating layer. This myelination allows electrical signals to travel more quickly along the axon through a process known as saltatory conduction, where the action potential jumps from one node of Ranvier to another. This efficiency in signal transmission is crucial for the fast and coordinated communication required for proper nervous system function.

While other functions are essential to the overall operation of the nervous system, they do not pertain specifically to myelin. For instance, myelin does not increase the size of neurons or produce neurotransmitters, which are produced by other cellular components in the neuron. Myelin's role is particularly significant in the context of both peripheral and central nervous systems, and a loss of myelin, as seen in conditions such as multiple sclerosis, can severely impact neural communication and overall health.