intrafusal fiber


Also found in: Encyclopedia.

intrafusal fiber

n.
Any of the muscle fibers present within a neuromuscular spindle.
References in periodicals archive ?
Standardized measurements were made of the area and diameter of the muscle spindle, mean cross-sectional area of intrafusal fibers, number of intrafusal fibers and thickness of the spindle capsule in the muscle spindle with the largest diameter.
The EMG activity during a stretch is triggered by impulses from the intrafusal fibers of the muscle spindles.
The therapeutic effects of BTX-A seemed to be due not only to partial denervation of extrafusal muscles but also to fusimotor denervation of intrafusal fibers that tonically control the sensitivity of spindle sensory afferents [19-21].
The motoneuron plays a role in changing the length of the intrafusal fibers and adjusting sensitivity of the muscle spindles.
The second type of muscle fiber, intrafusal fibers, functions within muscle spindles and is innervated by gamma motor neurons and sensory Ia neurons (see Figure 1 ).