56 



TOPOGRAPHICAL ANATOMY OF THE 



manner similar to the ending of the thoracic duct. The duct varies 

 within very wide limits in different individuals. It may even 

 happen that it is replaced by two or three vessels that enter the 

 venous system at a common point, or the duct may join the thoracic 

 duct. 



Dissection. — The thoracic part of the sympathetic nervous system 

 must now be examined. This is facilitated by the disarticulation of 

 those parts of the first pair of ribs that are still connected with the 

 vertebral column. 



A. transversa colli. 

 Second rib. \ 



A. intercostalis suprema. 



A. cervicalis profunda. 

 First thoracic nerve. ; 



First thoracic sympathetic ganglion. \ 



Eighth cervical nerve. 

 Seventh cervdcal nerve. \ 



A. vertebralis. 

 Rami communicantes of 

 second to seventh 

 cervical nerves. 

 Caudal cervical ganglion.-- — - 



Sympathetic cord. - 

 N. vagus. ' 



N. recurrens. 

 Truncus omocervicalis. ----- 



M. longus colli. 



■,-CEsophagus. 



Thoracic duct. 



A. costocervicalis. 



' Trachea. 



,. N. recurrens. 



Truncus 



brachiocephalicus. 

 - N. vagus. 



Cardiac nerves. 



N. phrenicus. 



V. jugularis sinistra. 



Truncus bicaroticus. 



A. thoracica externa. ' \ ' \ A. subclavia sinistra. 

 A. thoracica interna. 

 Fig. 23. — The blood-vessels and nerves within the first thn^e ribs of the left side. 

 Pars thoracalis systems sympathici. — Because of its close 

 juxtaposition to, and even confluence with, the first thoracic ganglion, 

 the caudal cervical ganglion should be examined by the dissector of the 

 thorax. 



In the neck the cord of the sympathetic and the vagus nerve are 

 contained in the same sheath. At the entrance to the thorax the 

 irregular caudal cervical ganglion ^ (ganglion cervicale caudale) is 

 developed on the sympathetic, and thereafter the two nerves separate. 

 On the right side of the body the ganglion usually lies along the 

 ' 7d77Xtoc (ganglion) [Gr.], a knot. 



