intrafusal fiber


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intrafusal fiber

n.
Any of the muscle fibers present within a neuromuscular spindle.
References in periodicals archive ?
The motoneuron plays a role in changing the length of the intrafusal fibers and adjusting sensitivity of the muscle spindles.
When intrafusal fibers contract, there is no direct contribution to muscle tension or muscle shortening.
2) This is due to the presence of cholinergic neuromuscular junctions between the a-motor neurons and the extrafusal fibers, and the 7-motor neurons and the intrafusal fibers which form the muscle spindle organ.