nodes of Ranvier

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Thân thiện
Definition

Noun: - Small gaps in the myelin sheath of medullated axons: The Nodes of Ranvier are periodic, uninsulated gaps in the myelin sheath that encases a nerve fiber (axon). These gaps are essential for the rapid saltatory conduction of nerve impulses.

Usage
  • The term is used in the fields of neuroscience, biology, and medicine to describe a specific anatomical and functional feature of myelinated neurons.
  • It is typically used in its plural form, "Nodes of Ranvier," as the structure consists of many repeated gaps along an axon.
  • It is a proper noun, named after the French histologist Louis-Antoine Ranvier.
Examples
  • In a scientific description:
    • The action potential jumps from one Node of Ranvier to the next, which speeds up neural transmission.
  • In an educational context:
    • The myelin sheath is interrupted at regular intervals by structures called the Nodes of Ranvier.
Advanced Usage
  • "Saltatory conduction at the Nodes of Ranvier": This phrase describes the process where an electrical nerve impulse leaps from node to node along the myelinated axon.
    • Saltatory conduction at the Nodes of Ranvier conserves energy for the neuron.
Variants and Related Words
  • Node of Ranvier (singular): Refers to a single gap in the myelin sheath.
  • Myelin sheath (noun): The insulating fatty layer that surrounds the axon, interrupted by the Nodes of Ranvier.
  • Internode (noun): The myelinated segment of axon two successive Nodes of Ranvier.
  • Axon (noun): The long threadlike part of a nerve cell along which impulses are conducted.
Synonyms
  • There are no direct common synonyms for this precise anatomical term. In general descriptive language, one might refer to:
    • Myelin gaps
    • Unmyelinated segments (though this is a more functional description)
Notes on Meaning
  • The term has a single, specific meaning in neuroanatomy. It does not have different everyday meanings.
  • The concept is crucial for understanding how signals travel quickly and efficiently in the nervous system.
Noun
  1. small gaps in the myelin sheath of medullated axons

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