RECIPROCAL TNNERVATTON 



817 



Fig. 214. Reciprocal innervation. Tracings made by myographs connected with E, an ex- 

 tensor muscle (vastus crureus), and F, a flexor muscle (semitendinosus), of a decerebrate cat. 

 At signal I the homolateral peroneal nerve was excited, causing contraction of the flexors and in- 

 hibition of the tone of the extensors. At signal // the flexors were again thrown into contraction by 

 exciting the contralateral peroneal nerve, and (without removing this stimulus) the contralateral 

 peroneal nerve was excited (as shown in the lower signal), with the result that the contraction 

 of the flexors was inhibited at the same time that the extensors contracted. On removal of the 

 latter stimulus, the former one reasserted its influence. This experiment demonstrates very clearly 

 the accurate coincidence of the reciprocal action. (From Sherrington.) 



