Receptor for inverse stretch reflex ?

Ans. is 'd' i.e., Golgi tendon argan Inverse stretch reflex (golgi tendon reflex) Golgi tendon reflex is a bisynaptic reflex, initiated by the Golgi tendon organ located in muscle tendons. This organ consists of a net-like (ramified) collection of knobby nerve endings among the fascicles of a tendon. There are 3-25 muscle fiber per golgi tendon organ. Golgi tendon organs are also stretch receptors. However, unlike the muscle spindle which acts as a length detecter, the Golgi-tendon organ acts as a muscle tension-detector. This difference in sensory function occurs because muscle spindle is located in parallel to the muscle fibers (extrafusal fibers) while the Golgi tendon organ is located in series to the muscle fibers (extrafusal fibers). Therefore, Golgi tendon organs are stimulated by both passive stretch and contraction of muscle (in contrast to muscle spindle which is stimulated by passive stretch but is inhibited by active contraction of muscle). Stimuli for golgi tendon reflex are both passive strech and active contraction of muscle. The golgi tendon organ is innervated by Aa sensory (afferent) fibers (type lb sensory). These afferent fibers terminate on an inhibitory interneuron in dorsal horn of grey matter in the spinal cord. These inhibitory interneuron terminates on the a-motor neuron (same a-motor neuron on which Ia (Aa) afferent of stretch reflex terminates) and has inhibitory effect on a-motor neuron. So, activation of Golgi tendon reflex results in relaxation of muscle.