Question 3
What are the nodes of Ranvier?
The right answer is the one marked above.
The places where the myelin sheath is absent. The impulse jumps from one node to the next rather than creeping the whole length of the axon, which is what makes conduction fast.
Collections of cell bodies are ganglia. The presence of the myelin sheath increases the speed of impulse conduction, and the gaps are the reason why.