Final answer:
Myelination, provided by myelin sheaths, increases neuronal conduction speed by insulating the axon and enabling action potentials to jump from node to node at the nodes of Ranvier.
Step-by-step explanation:
Myelination increases the speed of conduction in neurons by providing insulation (via myelin sheaths) and facilitating saltatory conduction. The myelin sheath, which is composed of fat-containing cells, wraps around the axon, creating segments along its length with gaps known as the nodes of Ranvier. These nodes contain voltage-gated Na+ and K+ channels, allowing the action potential to 'jump' from node to node rather than spreading smoothly along the entire membrane, thus speeding up the signal conduction significantly.
Myelin sheaths act as insulators that prevent current leak, hence reducing both the time constant and increasing the length constant for axonal conduction. This insulating property is critical for the efficient function of neurons; in diseases like multiple sclerosis, the myelin degenerates, leading to detrimental effects on signal transmission.