Muscle tone is maintained by ?

Ans. is 'c' i.e., Muscle spindleSensory receptors (stretch receptors) for stretch reflex are muscle spindles.Stretch reflex has two principal functions :1) To maintain muscle toneTone is a tendency of a muscle to resist being stretched.Muscle tone is not only impoant for maintaining posture but also facilitates locomotion and makes all voluntary movement smooth.2) To make muscles respond to stretch and releaseStretch reflex makes a muscle respond to stretch by contraction and to release by relaxation.both these responses, which oppose the triggering stimulus, help make voluntary movement smooth and graceful.