666 SYMPATHETIC AND OTHER SYSTEMS OF NERVES. 



DISTRIBUTION AND ACTION OF SACRAL AUTONOMIC NERVE FIBRES. 



The sacral autonomic nerve fibres all run to the pelvic nerve, 

 commonly called the nervus erigens. 



The origin of the pelvic nerve l varies somewhat in different animals, 



hypogastric nerve 

 m.o 



cervix uteri 



vagina 



pelvic nerve 

 (iieruus erigens) 

 from lit 

 9. m 



o.f 



urethral orifice 



FIG. 314. Left pelvic plexus of cat. The three sacral nerves and the first coccy- 

 geal nerve were cut peripherally of the spinal ganglia, and eleven days allowed 

 for degeneration. 



The numbers placed opposite each strand show the number of normal and of 

 degenerated fibres present in it, the number of normal fibres being placed 

 first. Thus 35*0 indicates that the strand contained thirty-five normal fibres 

 and not one degenerated ; m signifies many fibres (more than twenty-five) ; 

 s signifies some (ten to twenty-five) ; and /, a few fibres (nine or less). Thus 

 9.?7t signifies that nine sound and more than twenty-five degenerated fibres 

 were present in the strand. 



and in each animal varies in correspondence with the origin of the 

 lumbo-sacral nerves (cf. p. 633). In the cat, the second sacral nerve 



1 Langley and Anderson, Joiirn. PhysioL, Cambridge and London, 1896, vol. xx. p. 372. 



