Glossary / Lexicon

Muscle spindle is defined as a muscle stretch receptor oriented parallel to skeletal muscle fibers; the capsule portion is surrounded by afferent fibers, and intrafusal muscle fibers can alter the length of the capsule during muscle contraction and relaxation. Muscle spindle, moreover, is a proprioceptor sensitive to stretch and the rate of stretch that is concentrated primarily in the muscle belly between the fibers; receptor parallel to the muscle that responds to the stretch of a muscle