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

Myelin sheaths play a critical role in the nervous system by insulating nerve fibers, which significantly enhances the speed of electrical impulses traveling along the neurons. This insulation allows for a more efficient transmission of signals due to a phenomenon known as saltatory conduction, where the electrical impulses jump from one node of Ranvier to the next along the myelinated segments of the axon. The presence of myelin reduces the capacitance of the axon and increases the conduction velocity, which is vital for quick reflexes and coordinated movements.

The insulating properties of myelin not only speed up nerve impulses but also help to prevent signal loss, ensuring that electrical signals remain strong and effective as they travel through the nervous system. This is crucial for the functioning of both the central and peripheral nervous systems, allowing for rapid communication between different body parts and the brain.