ANATOMY OF THE DRILL. 



447 



The Sympathetic Nervous System. 



Both superior cervical ganglia (text-fig. 19, S.C.G) are pi-esent 

 and communicate with the glosso-pharyngeal, vagus, hypoglossal 

 and superior laryngeal nerves (b), and the cervical plexus (C.C.P) 

 Branches run to the pharyngeal (P.P) and carotid (C.A.P' 

 plexuses. 



Text-Hcure 21 . 



P) 



R.V. 



Posterior thoracic and abdominal parts of the vagus nerves. G.B : gastric branches ; 

 S.P. and So.P: branches to solar plexus; Sp.P : to splenic plexus; S.M.P .- to 

 superior mesenteric plexus ; S.Il.P : to left suprarenal plexus. 



The middle cervical ganglion (text-fig. 20, M.C.G) is onlv 

 present on the right side, and the Annulus of Vieussens (A.Y) is 

 interposed between the sympatiietics at the root of the neck and 

 the inferior cervical ganglia (I.C.G). The Annulus on each side 

 encircles the subclavian (S.A) and vertebral (V.A) arteries. 



No fusion occurs between the vagus and sympathetic in the 

 neck, and the communications between them take place at the 

 extremities of the cervical course. The left sympathetic gives off 

 cardiac nerves (C.B.S) at the root of the neck, and the right one 

 gives ofi' a cardiac cord from its middle ganglion (C.B.S'), tracheal 

 nerves (T.N), and communicating to the right recurrent larynoeal 

 nerve (C.R.L.N). "^ ^ 



The inferior cervical ganglia give off ascending branches which 

 accompany the vertebral arteries (V.A.N) and transverse twio-.s 

 which run to the brachial plexus (O.B.P). The main sympathetic 

 cords emerge from their posterior parts (T.C.S). 



30* 



