Final answer:
In myelinated neurons, ion flows occur only at the nodes of Ranvier due to the clustering of Na+ and K+ ion channels. This allows the action potential to 'jump' along the axon membrane from node to node, a process called saltatory conduction.
Step-by-step explanation:
In myelinated neurons, ion flows occur only at the nodes of Ranvier. This is because voltage-gated Na+ and K+ channels are clustered at these nodes in myelinated axons. The action potential signal 'jumps' along the axon membrane from node to node, a process called saltatory conduction. In contrast, unmyelinated axons have ion channels spread over the entire membrane surface and do not have nodes of Ranvier.