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Reciprocal Inhibition and Reciprocal Innervation

المؤلف:  John E. Hall, PhD

المصدر:  Guyton and Hall Textbook of Medical Physiology

الجزء والصفحة:  13th Edition , p703-704

2026-07-18

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We previously pointed out that excitation of one group of muscles is often associated with inhibition of another group. For instance, when a stretch reflex excites one muscle, it often simultaneously inhibits the antagonist muscles, which is the phenomenon of reciprocal inhibition, and the neuronal circuit that causes this reciprocal relation is called reciprocal innervation. Likewise, reciprocal relations often exist between the muscles on the two sides of the body, as exemplified by the flexor and extensor muscle reflexes described earlier.

Figure 1 shows a typical example of reciprocal inhibition. In this instance, a moderate but prolonged flexor reflex is elicited from one limb of the body; while this reflex is still being elicited, a stronger flexor reflex is elicited in the limb on the opposite side of the body. This stronger reflex sends reciprocal inhibitory signals to the first limb and depresses its degree of flexion. Finally, removal of the stronger reflex allows the original reflex to reassume its previous intensity.

Fig1. Myogram of a flexor reflex showing reciprocal inhibition caused by an inhibitory stimulus from a stronger flexor reflex on  the opposite side of the body.