The gaps in the myelin sheath that enable rapid conduction are known as what?

The gaps in the myelin sheath that enable rapid conduction are known as what?

• A. Endoneurons
• B. Nodes of Ranvier
• C. Dendrites
• D. Synaptic knobs

Answer: (B)

Gaps in the myelin sheath are the Nodes of Ranvier. These regular interruptions expose the axon membrane and are rich in voltage-gated sodium channels, so when an action potential reaches a node, it depolarizes there and the electrical signal jumps to the next node. This saltatory conduction from node to node speeds up nerve impulse transmission dramatically compared with continuous conduction along unmyelinated fibers. The other terms refer to different neural structures (endoneurial tissue, dendrites, or synaptic knobs) and do not describe gaps in the myelin sheath.

Gaps in the myelin sheath are the Nodes of Ranvier. These regular interruptions expose the axon membrane and are rich in voltage-gated sodium channels, so when an action potential reaches a node, it depolarizes there and the electrical signal jumps to the next node. This saltatory conduction from node to node speeds up nerve impulse transmission dramatically compared with continuous conduction along unmyelinated fibers. The other terms refer to different neural structures (endoneurial tissue, dendrites, or synaptic knobs) and do not describe gaps in the myelin sheath.