What is the function of the myelin sheath in neurons?

The myelin sheath is a critical component in the functioning of neurons, primarily because it serves to insulate the axon and increase the speed of signal transmission. This fatty layer, which wraps around the axons of many neurons, acts like insulation on an electrical wire, allowing electrical impulses to travel more quickly and efficiently along the nerve fiber.

This insulation reduces the loss of electrical signal during transmission and enables the creation of saltatory conduction, where the nerve impulse "jumps" from one node of Ranvier (gaps in the myelin sheath) to the next. This process significantly speeds up the propagation of nerve signals compared to unmyelinated axons, where the impulse travels continuously along the entire length of the axon.

While other functions, such as supporting cell structure, facilitating neurotransmission, and protecting the neuron, are important for overall neuronal health and function, the primary role of the myelin sheath is centered around its insulating properties and its contribution to enhanced signal speed.