Saltatory conduction accelerates nerve impulse transmission by enabling action potentials to jump between nodes of Ranvier.

Saltatory conduction accelerates nerve impulse transmission by enabling action potentials to jump between nodes of Ranvier.

• A. True
• B. False
• C. Only in unmyelinated fibers
• D. It slows conduction

Answer: (A)

Saltatory conduction speeds up nerve impulses by letting the depolarization jump from one node of Ranvier to the next in myelinated axons. The myelin sheath insulation between nodes increases membrane resistance and decreases capacitance, so the electrical signal travels quickly along the insulated internodes and is rapidly re-ignited at the next node where densely packed voltage-gated Na+ channels trigger another action potential. This jumping mechanism is much faster than the continuous conduction seen in unmyelinated fibers. It does not slow conduction and it does not occur in unmyelinated fibers.

Saltatory conduction speeds up nerve impulses by letting the depolarization jump from one node of Ranvier to the next in myelinated axons. The myelin sheath insulation between nodes increases membrane resistance and decreases capacitance, so the electrical signal travels quickly along the insulated internodes and is rapidly re-ignited at the next node where densely packed voltage-gated Na+ channels trigger another action potential. This jumping mechanism is much faster than the continuous conduction seen in unmyelinated fibers. It does not slow conduction and it does not occur in unmyelinated fibers.