THE THORAX. 



339 



eighth), superior intercostal vein (at the fifth or sixth 

 vertebrae) ; at the left, left lung and pleura, the oesopha- 

 gus ; at the right, the thoracic duct. For relations of 

 oesophagus to artery, see page 343. 



The Innominate Artery. Fig. 7 1 . Diag. 20. 



It arises from the transverse aorta near its beginning, 

 passes upward and outward to behind the right sterno- 



Diag. 23. TRANSVERSE SECTION OF THE THORAX JUST ABOVE THE DIAPHRAGM. 

 (/. S. H.)i, Left pneumogastric nerve. 2, Right pneumogastric nerve. 3, Thoracic 

 duct. 4, Azygos major, and 5, Minor veins. 



clavicular articulation, where it divides into the right com- 

 mon carotid and subclavian arteries. Its length is from 

 one and one-half to two inches. 



Relations. In front, first piece of the sternum, origins 

 of the right sternohyoid and sternothyroid muscles, right 

 sternoclavicular joint, remains of thymus gland, left in- 

 nominate and inferior thyroid veins, right cardiac nerves ; 



