Myelinated axons have large numbers of ion channels
A) along the entire length.
B) at the axon hillock and nodes of Ranvier.
C) only at the axon terminals.
D) only at the axon hillock.

Question

Quizplus · Accepted Answer

Myelinated axons have ion channels concentrated at the axon hillock and nodes of Ranvier. The myelin sheath insulates the axon and prevents the propagation of action potentials along the entire length of the axon, so ion channels are not necessary in those regions. However, at the nodes of Ranvier, the myelin sheath is interrupted, allowing action potentials to jump from node to node. The high concentration of ion channels at the nodes of Ranvier facilitates this process.

Myelinated Axons Have Large Numbers of Ion Channels