Neuroscience: A Journey Through the Brain

Main Page   Organization   Development   Neuron   Systems   About the site (Glossary)  References

The Structure of the Neuron: Myelin

Neuron Home    Size    Structure    Action Potentials    Classification

Structure sub categories: Axon    Boutons    Dendrites    Hillock    Myelin    Soma

Myelin is the insulating layer that surrounds many neurons throughout the nervous system. This membranous wrapping is provided in the CNS by Oligodendrocytes and in the PNS by Schwann Cells, and spirals around the axon. Because the axon fits inside the spiral myelin wrapping like a sword in its scabbard, the name myelin sheath describes the covering. The sheath is interrupted periodically, leaving exposed axonal membrane in short intervals. This region is called a Node of Ranvier.

Myelination is an important factor for the speed of axonal conduction in the form of action potentials.

Created and Maintained by: Melissa Davies
Last Updated: April 09, 2002 08:57 PM