SPINAL NERVES 



493 



anterior and posterior, both containing motor and sensory filaments, 

 which are distributed respectively to the anterior and the posterior parts 

 of the body. The anterior branches are the larger, and they supply the 

 limbs and all parts in front of the spinal column. 



The anterior branches of the upper four cervical nerves form the 

 cervical plexus ; and the four inferior cervical nerves, with the first 



Fig. 114. Cervical portion of 

 the spinal cord (Hirschfeld). 



Fig. 115. Dorsal portion of 

 the spinal cord (Hirschfeld). 



Fig. 116. Inferior por- 

 tion of the spinal cord, and 

 cauda equina (Hirschfeld) . 



i, anteroinferior wall of the fourth ventricle; 2, superior peduncle of the cerebellum; 3, middle 

 peduncle of the cerebellum; 4, inferior peduncle of the cerebellum ; 5, inferior portion of the posterior 

 median columns of the cord ; 6, glosso-pharyngeal nerve ; 7, pneumogastric ; 8, spinal accessory nerve ; 

 9, 9, 9, 9, dentated ligament; 10, 10, 10, 10, posterior roots of the spinal nerves ; u, n, n, n, posterior 

 lateral groove ; 12, 12, 12, 12, ganglia of the posterior roots of the nerves ; 13, 13, anterior roots of the 

 nerves ; 14, division of the nerves into two branches ; 15, lower extremity of the cord; 16, 16, coccygeal 

 ligament; 17, 17, cauda equina; I-VIII, cervical nerves ; I, II, III, IV-XII, dorsal nerves ; I, II-V, 

 lumbar nerves ; I-V, sacral nerves. 



dorsal, form the brachial plexus. The anterior branches of the dorsal 

 nerves, with the exception of the first, supply the walls of the chest and 

 abdomen. These nerves go directly to their distribution without form- 

 ing a plexus. The anterior branches of the upper four lumbar nerves 

 form the lumbar plexus. The anterior branch of the fifth lumbar nerve 

 and a branch from the fourth unite with the anterior branch of the first 



