DEGENERATIVE REACTIONS OF MUSCLE AND NERVE. 



6 7 I 



a stimulus for exciting contraction, on closing, opening, reversing, increasing, 

 and diminishing the current, but rather through its so-called polar effects. On 

 closing the circuit the nerve is thrown into irritation at the kathode, and on 

 opening the circuit at the anode. Then, during the period of closure of the circuit 

 through the nerve the irritability is increased at the kathode and by this means 

 a remedial influence may be exerted upon the nerve. In man, however, the special 

 conditions described on p. 662 should be kept in mind in the employment of 

 percutaneous galvanization. In the vicinity of the anode there is also increased 

 irritability. This is observed chiefly on repeated reversal of the current, but also 

 after closing and opening, or even on the uniform passage of the current. If the 

 increase in irritability obtained by means of the current be tested, it will be found 

 that as a result of the application of the current the irritability for the closing of a 



Gluteus maximus rr. 



Biceps femoris (cap. long.) m, 

 (Sciatic n.) 



Biceps femoris (cap. brev.) m, 

 (Sciatic n.) 



Peroneal n. 



Sciatic n. 



Adductor magnus m. 



(Obturator n.) 



Semitendinosus m. (Sciatic n.) 

 Semimembranosus m. 

 (Sciatic n.) 



Tibial n. 



Gastrocnemius m. (ext. cap.) 

 Gastrocnemius m. (ext. int.) 



Soleus m. 



Flex. dig. com. long. m. 

 Flex, hallucis long. m. 

 Tibial n. 



FIG. 238. Motor Points of the Sciatic Nerve and its Branches, the Peroneal and Tibial Nerves (after Eichhorst). 



current in the opposite direction and for. the opening of a current in the same 

 direction is increased. 



Furthermore, in the employment of the constant current its restorative effect 

 should be taken into account, chiefly the ascending current, as R. Heidenhain 

 has found that exhausted and enfeebled muscles can be refreshed by the passage 

 of a constant current. Finally, the constant current must be conceded a thera- 

 peutic influence by reason of its catalytic or cataphoric effects, in consequence 

 of which it exerts a solvent, decomposing, or dispersing action upon possible 

 accumulated products of inflammation or stagnation in nerve or muscle. The 

 current may, besides, exert a direct or reflex stimulating influence upon the nerves 

 of the blood-vessels and lymphatics. 



If the cause of the paralysis reside in the muscle itself, it is customary to 

 apply the induced current by means of sponge-electrodes directly to the muscle. 

 In case of primary lesions of the motor nerves the electrodes are applied to the 



