88 



THE PHYSIOLOGY OF MUSCLE AND NERVE. 



distinction is made between the cathodic and anodic effects. When, 

 however, the battery current is employed one may make the 

 stimulating electrode either anode or cathode, and under these 

 circumstances a marked difference is observed in the strength of 

 the current that it is necessary to use to get a response. With the 

 battery or galvanic current, in fact, one may distinguish four 

 stimuli, the closing and the opening shock when the stimulating 

 electrode is cathode and the closing and the opening shock when 



M. flexor carpi ulnaris 



M. flex, digit, siibl 

 (digit, indicis el 

 minimi) 



M. flexor digit, min. 

 M-Opponens digit. 



M. abductor pollic. brer. 

 M. opponens pollicis 



M. flex. poll. brcv. 



M. adductor pollic. brflT- 



Fig. 34. Motor points in upper extremity. 



it is anode. The contractions resulting from these four stimuli are 

 designated usually as follows : The cathodol closing contraction, 

 CCC; the cathodal opening contraction, C O C; the anodal clos- 

 ing contraction, A C C; and the anodal opening contraction, 

 A O C. Their relative efficiency as stimuli is given by the sequence 

 CCC > ACC > AOC> COC, although this sequence is subject 

 to some individual variation. Certain pathological or traumatic 

 lesions that cause the degeneration of the nerves may be revealed 



