Final answer:
The Nodes of Ranvier are the regions of an axon's plasma membrane that exhibit voltage-gated Na+ and K+ channels, allowing action potentials to jump from node to node and facilitating rapid neural transmission.
Step-by-step explanation:
The plasma membrane of an axon exhibits voltage-gated Na+ and K+ channels at the Nodes of Ranvier. These nodes are gaps in the myelin sheath that encase the axon, which is critical for the rapid conduction of electrical impulses along myelinated neurons. The action potential, or the electrical signal, jumps from one node to the next in a process known as 'saltatory conduction,' greatly increasing the speed of neural transmission. Unlike nodes, the axon hillock, initial segment, and axon terminals play different roles in neuron function. The initial segment, located just after the axon hillock, does contain a high density of voltage-gated Na+ channels and is where action potentials are initiated, but it is not the region described in the question regarding the expression of these channels along the axon for impulse transmission.