Psychology Wiki
Register
Advertisement

Assessment | Biopsychology | Comparative | Cognitive | Developmental | Language | Individual differences | Personality | Philosophy | Social |
Methods | Statistics | Clinical | Educational | Industrial | Professional items | World psychology |

Biological: Behavioural genetics · Evolutionary psychology · Neuroanatomy · Neurochemistry · Neuroendocrinology · Neuroscience · Psychoneuroimmunology · Physiological Psychology · Psychopharmacology (Index, Outline)


Extrafusal muscle fiber
[[Image:|190px|center|]]
Latin myofibra extrafusalis
Gray's subject #
System
MeSH [1]
[[Image:|190px|center|]]

Extrafusal muscle fiber is a term given to standard muscle fibers as to distinguish them from intrafusal muscle fibers. Extrafusal muscle fibers are innervated by alpha motor neurons and generate tension by contracting, thereby allowing for skeletal movement. 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 contratile ends and thus serve as a sensory proprioceptor.

The alpha motor neuron and the extrafusal muscle fibers it innervates make up the motor unit. 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.

See also[]

References[]


External links[]


This page uses Creative Commons Licensed content from Wikipedia (view authors).
Advertisement