Myelinated Axons

Saltatory propagation occurs in myelinated axons, where the signal "jumps" from one node to the next.
At the axon hillock, initial sodium channels initiate the action potential.
Myelin's insulation allows positive ions to move rapidly through the myelinated region.
These sodium ions cause the next sodium channel to reach the threshold, propagating the action potential.
Fewer sodium channels are needed in myelinated regions due to the insulation, which allows sodium ions to travel farther and faster.
Myelination reduces the overall number of sodium and potassium channels required along the axon's length.
Channels are primarily needed at the nodes of Ranvier to propagate the signal.

Acts as an insulator, speeding up the transmission of electrical signals along the axon.
Allows for the action potential to "jump" between the nodes of Ranvier, a process known as saltatory conduction.

Myelinated regions of the axon have a lower density of ion channels.
Nodes of Ranvier are rich in voltage-gated sodium and potassium channels, which are essential for the regeneration of the action potential.