Internodal segment

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Internodal segment
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Diagram of longitudinal sections of medullated nerve fibers.
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Medullated nerve fibers stained with silver nitrate.
Details
Part of Axon of nerve fiber
System Nervous system
Identifiers
Latin segmentum internodale
TH H2.00.06.2.03028
Anatomical terms of microanatomy

An internodal segment (or internode) is the portion of a nerve fiber between two Nodes of Ranvier. The neurolemma or primitive sheath is not interrupted at the nodes, but passes over them as a continuous membrane.

Node of Ranvier An axon part that is a gap in the myelin where voltage-gated sodium channels cluster and saltatory conduction is executed.

Nodes of Ranvier, also known as myelin-sheath gaps, occur along a myelinated axon where the axolemma is exposed to the extracellular space. Nodes of Ranvier are uninsulated and highly enriched in ion channels, allowing them to participate in the exchange of ions required to regenerate the action potential. Nerve conduction in myelinated axons is referred to as saltatory conduction due to the manner in which the action potential seems to "jump" from one node to the next along the axon. This results in faster conduction of the action potential.

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Tracheobronchial lymph nodes

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Preaortic lymph nodes

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Inferior mesenteric lymph nodes

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Internal iliac lymph nodes

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Mastoid lymph nodes

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Supratrochlear lymph nodes

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Deep cervical lymph nodes

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Supraclavicular lymph nodes

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Superficial cervical lymph nodes

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Buccinator lymph node

The buccinator lymph node or nodes are one or more lymph nodes placed on the Buccinator opposite the angle of the mouth.

Submandibular lymph nodes

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Superior mesenteric lymph nodes

The superior mesenteric lymph nodes may be divided into three principal groups:

Celiac lymph nodes

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Splenic lymph nodes

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Parotid lymph nodes

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Infraauricular deep parotid lymph nodes

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References

This article incorporates text in the public domain from page 727 of the 20th edition of Gray's Anatomy (1918)

The public domain consists of all the creative works to which no exclusive intellectual property rights apply. Those rights may have expired, been forfeited, expressly waived, or may be inapplicable.

<i>Grays Anatomy</i> English-language textbook of human anatomy

Gray's Anatomy is an English language textbook of human anatomy originally written by Henry Gray and illustrated by Henry Vandyke Carter. Earlier editions were called Anatomy: Descriptive and Surgical, Anatomy of the Human Body and Gray's Anatomy: Descriptive and Applied, but the book's name is commonly shortened to, and later editions are titled, Gray's Anatomy. The book is widely regarded as an extremely influential work on the subject, and has continued to be revised and republished from its initial publication in 1858 to the present day. The latest edition of the book, the 41st, was published in September 2015.