Jump to content

Extrafusal muscle fiber: Difference between revisions

From Wikipedia, the free encyclopedia
Content deleted Content added
tag
top: minor ce
Line 17: Line 17:
| PartOf = [[Skeletal muscle]]
| PartOf = [[Skeletal muscle]]
}}
}}
'''Extrafusal muscle fibers''' are the [[skeletal muscle|skeletal]] standard [[muscle fiber]]s that are innervated by [[alpha motor neuron]]s and generate tension by contracting, thereby allowing for skeletal movement. They make up the large mass of skeletal [[striated muscle tissue|muscle tissue]] and are attached to bone by fibrous tissue extensions ([[tendon]]s).
'''Extrafusal muscle fibers''' are the standard [[Skeletal muscle#Skeletal muscle fibers|skeletal muscle fiber]]s that are innervated by [[alpha motor neuron]]s and generate tension by contracting, thereby allowing for skeletal movement. They make up the large mass of skeletal [[striated muscle tissue]] and are attached to bone by fibrous tissue extensions ([[tendon]]s).


Each alpha motor neuron and the extrafusal muscle fibers innervated by it make up a [[motor unit]].<ref name="Purves">{{cite book|last1=Purves|first1=Dale | name-list-style = vanc |title=Neuroscience|date=2011|publisher=Sinauer|location=Sunderland, Mass.|isbn=978-0-87893-695-3|pages=355–358|edition= 5th}}</ref> The connection between the alpha motor neuron and the extrafusal muscle fiber is a [[neuromuscular junction]], where the neuron's signal, the [[action potential]], is transduced to the muscle fiber by the [[neurotransmitter]] [[acetylcholine]].
Each alpha motor neuron and the extrafusal muscle fibers innervated by it make up a [[motor unit]].<ref name="Purves">{{cite book|last1=Purves|first1=Dale | name-list-style = vanc |title=Neuroscience|date=2011|publisher=Sinauer|location=Sunderland, Mass.|isbn=978-0-87893-695-3|pages=355–358|edition= 5th}}</ref> The connection between the alpha motor neuron and the extrafusal muscle fiber is a [[neuromuscular junction]], where the neuron's signal, the [[action potential]], is transduced to the muscle fiber by the [[neurotransmitter]] [[acetylcholine]].

Revision as of 07:18, 15 May 2021

Extrafusal muscle fiber
Details
Part ofSkeletal muscle
Identifiers
Latinmyofibra extrafusalis
THH3.03.00.0.00007
Anatomical terminology

Extrafusal muscle fibers are the standard skeletal muscle fibers that are innervated by alpha motor neurons and generate tension by contracting, thereby allowing for skeletal movement. They make up the large mass of skeletal striated muscle tissue and are attached to bone by fibrous tissue extensions (tendons).

Each alpha motor neuron and the extrafusal muscle fibers innervated by it make up a motor unit.[1] The connection between the alpha motor neuron and the extrafusal muscle fiber is a neuromuscular junction, where the neuron's signal, the action potential, is transduced to the muscle fiber by the neurotransmitter acetylcholine.

Extrafusal muscle fibers are not to be confused with intrafusal muscle fibers, which are innervated by sensory nerve endings in central noncontractile parts and by gamma motor neurons in contractile ends and thus serve as a sensory proprioceptor.

Extrafusal muscle fibers can be generated in vitro (in a dish) from pluripotent stem cells through directed differentiation.[2] This allows study of their formation and physiology.

See also

References

  1. ^ Purves D (2011). Neuroscience (5th ed.). Sunderland, Mass.: Sinauer. pp. 355–358. ISBN 978-0-87893-695-3.
  2. ^ Chal J, Oginuma M, Al Tanoury Z, Gobert B, Sumara O, Hick A, Bousson F, Zidouni Y, Mursch C, Moncuquet P, Tassy O, Vincent S, Miyanari A, Bera A, Garnier JM, Guevara G, Hestin M, Kennedy L, Hayashi S, Drayton B, Cherrier T, Gayraud-Morel B, Gussoni E, Relaix F, Tajbakhsh S, Pourquié O (September 2015). "Differentiation of pluripotent stem cells to muscle fiber to model Duchenne muscular dystrophy". Nature Biotechnology. 33 (9): 962–9. doi:10.1038/nbt.3297. PMID 26237517. S2CID 21241434. Closed access icon

Further reading