Here's why:
* Myelin sheath: Myelin is a fatty substance that wraps around axons, creating a layer of insulation. This insulation prevents the electrical signal from leaking out, allowing it to travel much faster.
* Saltatory conduction: The signal jumps from one gap in the myelin sheath (called a Node of Ranvier) to the next, rather than traveling continuously along the entire axon. This "jumping" process is called saltatory conduction and is significantly faster than continuous conduction.
Other factors influencing conduction speed:
* Axon diameter: Larger diameter axons have less resistance to the flow of electrical current, leading to faster conduction.
* Temperature: Conduction speed increases with temperature.
Therefore, myelinated axons with large diameters and in warm temperatures experience the fastest impulse conduction.
