Nodes of Ranvier are gaps in the myelin sheath of peripheral neurons that allow saltatory conduction.

Nodes of Ranvier are gaps in the myelin sheath of peripheral neurons that allow saltatory conduction.

• A. True
• B. False
• C. They are not present in peripheral nerves
• D. They are sites of neurotransmitter release

Answer: (A)

Nodes of Ranvier are gaps in the myelin sheath that expose the axon membrane in myelinated peripheral nerves. These exposed regions harbor a high density of voltage-gated Na+ channels, so each node can regenerate the action potential as it passes. The myelin between nodes insulates the axon, reducing membrane capacitance and increasing resistance, which allows the impulse to jump from node to node—saltatory conduction—greatly speeding transmission. They are not sites of neurotransmitter release; release occurs at synaptic terminals. In short, this statement is true: the gaps enable saltatory conduction in peripheral neurons.

Nodes of Ranvier are gaps in the myelin sheath that expose the axon membrane in myelinated peripheral nerves. These exposed regions harbor a high density of voltage-gated Na+ channels, so each node can regenerate the action potential as it passes. The myelin between nodes insulates the axon, reducing membrane capacitance and increasing resistance, which allows the impulse to jump from node to node—saltatory conduction—greatly speeding transmission. They are not sites of neurotransmitter release; release occurs at synaptic terminals. In short, this statement is true: the gaps enable saltatory conduction in peripheral neurons.