Anatomy

Neuron

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Neuron, Nerve Cell, Neural Cell, Synapse, Neuraxis Tract, Nerve Fasciculus, Neuraxis Peduncle, Neuraxis Lemniscus, Neural Nucleus, Dendrite, Neuron Cell Body, Neuron Soma, Perikaryon, Axon, Myelin Sheath

  • Definitions
  1. Neuron
    1. Conducting cell of the neurologic system which receives, conducts and transmits small electrical signals
  2. Synapse
    1. Connections between Neurons in which they communicate via chemical signals (neurotransmitters)
  3. Neurologic Pathway
    1. Chain of communicating Neurons
  4. Neuraxis Tract (or fasciculus, peduncle or lemniscus)
    1. Bundle of axons in a pathway within the Central Nervous System (CNS)
  5. Nerve
    1. Bundle of axons in a pathway within the peripheral nervous system
  6. Neural Nucleus
    1. Group of Neuron cell bodies (soma) with attached group of axons (nerve tracts)
    2. Includes brain nucleii, Cranial Nerve nucleii, cerebellar nucleii and spinal cord nucleii
    3. Ganglia are the peripheral nerve versions of the CNS neural neuclei
  • Physiology
  1. Neurons are specialized cells capable of tranmsitting an electrical signal
  2. Neuron types
    1. Sensory Neurons
    2. Motor Neurons
    3. Interneurons (interconnections between Neurons forming a pathway)
  3. Group of Neurons
    1. Peripheral nervous system
      1. Nerves
    2. Central Nervous System (interchangeable names)
      1. Nerve Tract
      2. Fasciculus
      3. Lemniscus
      4. Peduncle
  • Components
  1. Dendrites
    1. Tree-like structures that receive signals from other Neurons
  2. Cell Body (Soma)
    1. Nucleus
    2. Cytoplasm (Perikaryon)
  3. Axon
    1. Transmits signal from cell body to axon terminals
    2. Myelin Sheath
      1. Most axons are insulated with a thin layer of cells to conserve and speed electrical transmission
      2. Myelinated axons appear as white matter (while Neuron cell bodies appear as gray matter)
  4. Neurotransmitters
    1. Released from axon terminals to transmit a signal into Synapse (inter-Neuron space)
  • Images
  1. NeuroCellGrayBB629.gif Lewis (1918) Gray's Anatomy 20th ed (in public domain at Yahoo or BartleBy)
  2. NeuroCellGrayBB626.gif Lewis (1918) Gray's Anatomy 20th ed (in public domain at Yahoo or BartleBy)
  3. NeuroCellGrayBB625.gif Lewis (1918) Gray's Anatomy 20th ed (in public domain at Yahoo or BartleBy)