Nodes of Ranvier

Intro | Axon | Axon Hillock | Dendrites | Myelin Sheath | Nodes of Ranvier | Soma | Synapse | Terminal Buttons

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The gaps (approximately 1 micrometer wide) formed between myelin sheath cells long the axons are called Nodes of Ranvier. Since fat serves as a good insulator, the myelin sheaths speed the rate of transmission of an electrical impulse along the axon. The electrical impulse jumps from one node to the next at a rate as fast as 120 meters/second. This rapid rate of conduction is called saltatory conduction. Myelinated axons are rare in the autonomic nervous system. Invertebrates do not have myelinated sheaths.