DISSECTION OF THE DOG 



61 



The branches of that part of the aorta now under consideration are as 

 follows : (1) Nine or ten intercostal arteries arising from its dorsal aspect ; 

 (2) two or three small bronchial arteries arising either from the aorta itself or 

 from the first intercostal artery, and supplying the bronchial lymph-glands 

 and the oesophagus ; (3) two or three small oesophageal arteries leaving the 

 ventral aspect of the vessel. 



Ductus thoracictjs.— By means of the thoracic duct the lymph from the 

 whole body, with the exception of that from the right side of the thorax, the 



(Esophagus 



Truncus (esophageus dorsatis 

 I 



I 11. splanchnicus major 



I n. splanchnicus mit 



1. vaults ertiuncui sy-nvitalhicus 



I 



\ 



Ganglion thoracale 

 1 primum 



Ganglion ca;liac 

 Vmlriculus 



'sophatjus 



n. recufrtfiis 



Ganglion cermccde caudate 



n. phfenicus 



Truncus cesophcugeus ventrat 



Diaphragma 

 Flo. 24. — Diagram of part of the sympathetic nervous system. 



right thoracic hmb, and the right side of the head and neck, gains the venous 

 system. The thoracic duct begins in the abdomen between the lumbar 

 parts of the diaphragm, as a dilation known as the cisterna chyli. It enters the 

 thorax on the right side of the aorta, between this vessel and the vena azygos. 



Variable as is its thoracic course it may be said generally that, incUning 

 slightly towards the left, the duct passes for some distance through the chest 

 dorsal to the oesophagus. Afterwards it crosses the oesophagus on the left, and 

 finally opens into the left innominate vein. 



The duct is nearly always double for a greater or shorter part of its course, 

 frequent intercommunications existing between the two vessels. 



Pabs thoeacalis systems sympathici. — A large, elongated gangUon, 

 the first thoracic ganglion (ganghon thoracale primum), hes between^ the longus 



