THE SPINAL NERVES 



355 



of these rami supply the muscles of the lateral and ventral body wall, and 

 the afferent fibers end in the integument of the same regions. 



At the points where the anterior and lateral terminal rami arise, 

 connecting loops may extend from one spinal nerve to another. Thus, in 

 the cervical region superficial and deep nerve plexuses are formed. The 



Gang, acusticum 

 Gang, semilunare n. V 



Cerebellum I N.VI- 



Vesicula auditiva 

 ; Gang, radicis n. IX 

 Gang, petrosum 



Gang, radicis n. X 



K. UJ 

 N.IV- 



N. frontalis 



N. nasociliaris "' 



N. maxillaris 



N. mandibularis ' 



Gang, geniail, il n m 



N. chorda tympani 



Cor- 



Diaphragma *" 

 Hepar 

 I Co. 



N. tibialis 

 tf, peroneus -' 



Tubus digest. 



'Gang. Froriep 

 .N hypoglossus 



l.C. 



:--- N.Xl 



-Gang, nodos. 



ft. desc. cerv. 

 . Rami kyoid. 

 (A nsa kypaglossi) 

 N. Uusrulomlait. 

 ' N. axiltaris 

 "N. pkrenicus 

 -- A. medianus 

 - K. radialis 

 "N. ulnaris 

 I Th. 



R. posterior 

 R. terminalis laleralis 

 IS. R. terminalis anterior 



K. femora/ ! \IL. 



N. obturator Mesonephros 



Nn. ilioing. et hypogastr. 



P IG - 359- Reconstruction of the nervous system of a 10 mm. embryo (Streeter). X 



12. 



deep cervical plexus forms the ansa hypoglossi and the phrenic nerve 



(Fig- 359)- 



The Brachial and Lumbo-sacral Plexuses. The nerves supplying the 

 arm and leg also unite to form plexuses. In embryos of 10 mm. (Fig. 359) 

 the trunks of the last four cervical nerves and of the first thoracic are united 

 to form a flattened plate, the anlage of the brachial plexus. From this 



