Node of Ranvier

Node of Ranvier

The Node of Ranvier (also known as myelin sheath gap) is a small gap in the myelin sheath of a nerve where the axon is exposed. Named after French anatomist Louis-Antoine Ranvier, who first described the node in 1878, it plays a crucial role in the conduction of nerve impulses.

Structure

Nodes of Ranvier are typically 1 micrometer in length. They are found at regular intervals along the axon, between segments of the myelin sheath produced by Schwann cells in the peripheral nervous system and oligodendrocytes in the central nervous system.

Function

The primary function of the Node of Ranvier is to facilitate the rapid conduction of nerve impulses. This is achieved through a process known as saltatory conduction, where the electrical impulse jumps from one node to the next, rather than traveling the entire length of the axon.

Clinical significance

Damage to the nodes of Ranvier, or to the myelin sheath itself, can impair the conduction of nerve impulses and lead to neurological disorders such as multiple sclerosis and Guillain-Barré syndrome.

See also

• Myelin
• Saltatory conduction
• Schwann cell
• Oligodendrocyte

References

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External links

• Node of Ranvier at Encyclopædia Britannica

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