So 



THE POCKET ANATOMY 



Branches. Right and left coronary arteries distributed to 

 heart (vide Heart). 



Transverse part, which runs much more from before back- 

 wards than from right to left, so that relations in front are also 

 to the left, and those behind to the right, commences at upper 

 border of 2nd right costal cartilage, arching backwards over 

 root of left lung, as far as inferior border of left side of body of 

 4th dorsal vertebra. 



Branches : 



Innominate (i| to 2 inches long) : arises at commencement 

 of transverse part, ascends to right beneath sternum, dividing 

 opposite right sterno-clavicular articulation into right common 

 carotid and right subclavian arteries (vide Arteries of Head and 

 Neck, pp. 59 and 64). 



Relations of the Innominate. Lies behind manubrium and 

 origins of right sterno-hyoid and sterno-thyroid muscles, 

 thymus gland and left innominate and right inferior thyroid 

 veins. Trachea at first behind, but above to left side, where 

 artery lies on pleura. On the right side lie the right innomi- 

 nate vein and right phrenic nerve. On the left side, below is 

 the left common carotid, above the trachea. The innominate 

 occasionally gives off a branch, the arteria thyroidea ima, which 

 passes in front of trachea to thyroid gland. 



Left common carotid (vide Arteries of Head and Neck, p. 64). 



THE DESCENDING THORACIC AORTA. 



Extent. From lower border of 4th dorsal vertebra (left 

 side) to aortic opening in front of body of i2th dorsal ver- 

 tebra. 



