Beta motor neuron

Beta motor neurons (β motor neurons), also called beta motoneurons, are a kind of

. However, the larger diameter alpha motor fibers require higher conduction velocity than beta and gamma.

Types

There are two kinds of beta motor neuron (as gamma motor neuron) that include:

• Static beta motor neurons. These motor neurons innervate nuclear chain fibers of muscle spindles, with collaterals to extrafusal muscle fibers.
• Dynamic beta motor neurons. The dynamic type innervates
  nuclear bag fibers
  of muscle spindles, with collaterals to extrafusal muscle fibers.

Gamma motor neurons innervate only intrafusal fibers of muscle spindles, but extrafusal fibers (i.e. slow and fast fibers) are innervated by alpha motoneurons.

See also

• Nerve fiber
• Type Ia sensory fiber
• Type II sensory fiber

References

• Williams & Warwick. Gray's Anatomy. Thirty-seventh edition. Churchill Livingstone.
  ISBN 0-443-04177-6
• https://web.archive.org/web/20100725065352/https://musom.marshall.edu/anatomy/grosshom/Musclesensory.html