Myelin and Neural Speed
Insulation for axons
What is myelin?
Myelin is a lipid-rich insulating layer wrapped around some axons. It speeds signal transmission by helping electrical impulses travel efficiently along the nerve fiber.
Who makes it?
In the central nervous system, oligodendrocytes make myelin. In the peripheral nervous system, Schwann cells do this job. Myelin is essential for fast and reliable communication.
Why myelin matters
Myelin helps the brain send information faster while using less energy.
Molecular basis of speed
Myelin concentrates ion channels at specific axon regions, allowing action potentials to 'jump' between gaps called nodes of Ranvier. This is called saltatory conduction.
What is saltatory conduction?
Saltatory conduction refers to fast signal propagation along myelinated axons.
Correct answer: Signal jumping between nodes in myelinated axons
Which cell type makes myelin in the peripheral nervous system?
Schwann cells produce myelin in peripheral nerves.
Correct answer: Schwann cells
Myelin producers
Oligodendrocytes
- Myelin in the central nervous system
- One cell can myelinate multiple axons
Schwann cells
- Myelin in the peripheral nervous system
- Usually myelinate one axon segment