Final answer:
Saltatory conduction is exclusive to myelinated nerve fibers and involves the rapid jumping of action potentials from one node of Ranvier to the next, facilitating faster and more efficient nerve signal transmission.
Step-by-step explanation:
Saltatory conduction occurs only in myelinated nerve fibers. This type of neural impulse propagation is characterized by the action potential 'jumping' from one node of Ranvier to the next rather than moving in a continuous flow along the axon, as it does in unmyelinated fibers. The presence of a myelin sheath in myelinated nerve fibers insulates the axon and prevents the ion flow along the axon's entire length, enabling saltatory conduction. This process allows rapid and efficient signal transmission along the nerve fiber.
In contrast, propagation along an unmyelinated axon, known as continuous conduction, is slower because voltage-gated Na+ channels are consistently opening along the membrane, resulting in a continuous influx of sodium ions. Myelination thus dramatically increases the speed at which nerve impulses are conducted. To summarize, saltatory conduction is exclusive to myelinated nerve fibers and is facilitated by the unique structure of these fibers, which includes the nodes of Ranvier where the action potentials are regenerated.