THE SUBCLAVIAN ARTERIES. 



515 



hyoid, and Sterno-thyroid muscles, and another layer of the deep fascia. It is 

 crossed by the internal jugular and vertebral veins, and by the pneumogastric 

 and the cardiac branches of the sympathetic. A loop of the sympathetic nerve 

 itself also crosses the artery, forming a ring around the vessels. The anterior 

 jugular vein passes outward in front of the artery but is not in contact with it, 

 being separated from it by the Sterno-hyoid and Sterno-thyroid muscles. Below 

 and behind the artery is the pleura, which separates it from the apex of the lung ; 

 behind is the cord of the sympathetic nerve ; the recurrent laryngeal nerve winds 

 round the lower and back part of the vessel. 



Phrenic nerve. 



Vertebral artery. 



Inferior thyroid artery. 



artery. 

 Supra- 

 scapular 



nerve. W 



eumo- 

 gastric 

 nerve. 



Subdavian 



artery. 



^External jugu- 

 lar vein. 

 Right innomi- 



nate vein, 

 fnnomi- 



artery. 



Profunda artery. 

 -Muscido-spiral nerve. 



FIG. 298. The subclavian artery, showing its relations. (From a preparation in the Museum of the Royal 

 College of Surgeons of England.) 



PLAN OF RELATIONS OF FIRST PORTION OF THE RIGHT SUBCLAVIAN ARTERY. 



In front. 



Skin, superficial fascia. 

 Platysma, deep fascia. 

 Clavicular origin of Stcrno-mastoid. 

 Sterno-hyoid and Sterno-thyroid. 

 Anterior jugular, Internal jugular, and vertebral veins. 

 Pneumogastric and cardiac nerves. 

 Loop from the sympathetic. 



