The protective coating around nerve fibers that increases conduction speed is called?

• A. Node of Ranvier
• B. Myelin sheath
• C. Schwann cell
• D. Axon hillock

Answer: (B)

Myelination speeds nerve impulses by insulating the axon and enabling saltatory conduction. The protective coating around nerve fibers is the myelin sheath. This sheath wraps around the axon, reducing leakage of current and lowering the membrane’s capacitance, so the action potential can jump from one node of Ranvier to the next rather than propagate continuously. Those gaps are where ion channels cluster, allowing rapid boosts as the signal leaps along the fiber. The term Schwann cell refers to the glial cell that forms this coating in the peripheral nervous system, while the axon hillock is the region where the action potential typically starts.