Neuroscience: A Journey Through the Brain
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The Structure of the Neuron: Myelin
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.
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Last Updated: April 09, 2002 08:57 PM