Reflexes control muscle length and force through monosynaptic reflexes like the stretch reflex seen in the knee jerk reaction. Muscle spindles contain fibers that detect changes in muscle length and send signals to the CNS. The CNS then coordinates α and γ motor neurons to contract or relax muscles as needed through reciprocal innervation and regulation of muscle tone.

1. REFLEXES FOR MUSCLE LENGTH & MUSCLE FORCE
General properties of reflexes
Monosynaptic reflexes: the stretch reflex
Knee jerk reflex
Structure of muscle spindle
α – γ coactivation
Stimulation of afferents/efferent
Control of γ-efferent discharge
Reciprocal innervation
Inverse stretch reflex – MUSCLE TONE