What is the role of the axon's myelin sheath?

The axon's myelin sheath plays a crucial role in increasing the speed of electrical impulses, also known as action potentials, along the length of the axon. Myelin is a fatty substance that wraps around the axon in segments, creating insulated regions separated by nodes of Ranvier. This insulation allows the electrical impulses to jump from one node to the next, a process called saltatory conduction. As a result, myelinated axons conduct impulses much more rapidly compared to unmyelinated axons. This efficiency is vital for quick communication between nerve cells and for the overall functioning of the nervous system.

Other options pertain to different functions within the neuronal framework. For example, while neurons do relay information through their synapses, it is not the role of the myelin sheath. Similarly, neurotransmitter production is performed primarily by the neuron’s cell body and synaptic terminals, not by myelin. Memory storage is a complex process that involves various brain structures and synaptic changes, rather than being attributed to any single component like myelin. Thus, the primary function of the myelin sheath centers on enhancing the speed of signal transmission in neurons.