A fusiform mechanoreceptor (specifically a stretch receptor) within the skeletal muscle, composed of a bundle of striated muscle fibers innervated by sensory neurons within a connective tissue sheath. The structure is sensitive to stretch or change in the length of the muscle and is involved in the reflex stretch or automatic regulation of skeletal muscle length.
The muscle spindles are arranged parallel to the muscle fibers. They are responsible for the myotatic reflex or stretch reflex.
- stretch receptor