506 NEUROLOGY. 



The Inferior branches send twigs to the sympathetic, and 

 branches which communicate with one another. 



That of the first lumbar nerve receives a branch from the last 

 dorsal, and turning backwards under the transverse process of 

 the second lumbar vertebra, passes between the transversalis 

 abdominis and internal oblique, to which it sends filaments, and 

 terminates in the rectus muscle. Near its origin, it gives off a 

 perforating branch which, passing through the abdominal muscles, 

 terminates in numerous cutaneous filaments. 



The inferior branch of the second lumbar nerve has similar 

 communicating branches to the first, and two perforating nerves 

 which, receiving a small branch from the third, descend under 

 the skin of the internal and anterior face of the thigh, and are 

 distributed to the skin of the flank and the crural region. 



The inferior branch of the third nerve, besides its communicat- 

 ing branches, sends usually three branches downwards and outwards 

 to the inguinal canal, where they ramify in the cremaster muscle ; 

 it also furnishes numerous twigs to the psoas magnus. One of 

 the inguinal nerves generally unites with a large branch of the 

 fourth nerve. 



The inferior branch of the fourth lumbar nerve, besides the 

 branches common to all, gives a large branch to the lumbo-sacral 

 plexus, and a long branch which unites with an inguinal branch 

 from the third. It is then directed downwards to the thigh, 

 where it terminates in numerous cutaneous and aponeurotic 

 branches. 



The fifth lumbar gives a large branch to the lumbo-sacral 

 plexus, and branches to the psoas parvus. 



The sixth lumbar is the principal branch of the lumbo-sacral 

 plexus. 



SACRAL NERVES (5 pairs). 



The sacral nerves, which diminish in size from the first to the 

 last, have their origin close to each other, their roots surrounding 

 the conus medullaris, in which the spinal cord terminates, and by 

 which it extends into the canal of the sacrum. With the coccy- 

 geals they form the nerve tuft known as the cauda equina. 



The superior branches of the sacral nerves leave the spinal 

 canal through the superior sacral foramina, and are distributed 

 to the muscles of the superior region of the sacrum, and 

 terminate in the skin of the croup. 



