Final answer:
The term for the insulating sheath which facilitates the rapid movement of the action potential down the axon is called the Myelin Sheath. The myelin sheath is produced by glial cells and contains periodic gaps known as Nodes of Ranvier, which help recharge the signal as it moves along the axon.
Step-by-step explanation:
The insulating sheath that facilitates rapid movement of the action potential down the axon is known as the Myelin Sheath. The myelin sheath acts as an insulator to prevent the electrical signal from dissipating as it travels down the axon. This is an essential function especially considering that the axon from a human motor neuron can be as long as a meter from the base of the spine to the toes.
The myelin sheath is produced by glial cells. Along the axon, there are gaps in the myelin sheath called Nodes of Ranvier. These nodes are sites where the signal is recharged as it travels along the axon.
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