Final answer:
The nodes of Ranvier are gaps in the myelin sheath along a neuron's axon, facilitating rapid transmission of electrical impulses through saltatory conduction.
Step-by-step explanation:
The nodes of Ranvier are gaps in the myelin sheath of neurons. These nodes are crucial for the rapid transmission of electrical impulses along an axon, as they contain voltage-gated K+ and Na+ channels. Action potentials jump from node to node in a process known as saltatory conduction, greatly increasing the speed of neural signals.