What is the function of the myelin sheath?

The myelin sheath plays a crucial role in the nervous system, primarily by insulating axons, which are long projections of nerve cells. This insulation is significant because it prevents the loss of electrical signals as they travel along the axon. Myelin increases the speed of electrical impulse conduction through a process called saltatory conduction, where the action potential jumps between the nodes of Ranvier, spaces along the axon that are not covered by myelin. As a result, the presence of myelin allows for quicker communication between neurons, facilitating efficient signal transmission across the nervous system. This is particularly important for rapid reflexes and coordinated movements. Understanding the critical role of the myelin sheath highlights why its integrity is essential for proper nervous system function and why damage to this sheath can lead to neurological disorders.