Extrafusal muscle fiber

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Extrafusal muscle fibers are a class of muscle fiber innervated by alpha motor neurons. Contraction of these fibers allows for movement. Extrafusal muscle fibers and associated alpha motor neurons are called a motor unit. The connection between alpha motor neuron and extrafusal muscle fiber is a neuromuscular junction.

[edit] External links

• Dorlands/Elsevier f_05/12360939

Muscle tissue v • d • e

skeletal muscle/general: epimysium, fascicle, perimysium, endomysium, muscle fiber, myofibril sarcomere (a, i, and h bands; z and m lines), myofilaments (thin filament/actin, thick filament/myosin, elastic filament/titin), tropomyosin, troponin neuromuscular junction, intrafusal muscle fibers, extrafusal muscle fiber, motor unit, muscle spindle, sliding filament mechanism myoblast, satellite cells, sarcoplasm, sarcolemma, sarcoplasmic reticulum, T-tubule cardiac muscle: myocardium, intercalated disc smooth muscle: calmodulin, vascular smooth muscle