440 



W ATOMY IX A XI TSHELL. 



now runs outward behind the Scalenus anticus muscle then downward under 

 the clavicle to the lower border of the first rib where it takes the name of axil- 

 lary. 'Hit' Scalenus anticus muscle divides this artery into three portions. 

 The portion internal to the muscle is the first portion, the portion behind it is 

 ;Ik second portion, and the portion < xternal to it is the third portion. 



'I'm: Relations of First Portion ok the Right Subclavian Artery. 

 1\ Front. — (1) Skin. (2) Superficial fascia. (.'!) Platysma and deep fascia, 

 l Clavicular origin of Sterno-mastoid, (5) Sterno-hyoid, (6) Sterno-thyroid, 

 (7) Anterior jugular, (8) Internal jugular, (9) Vertebral veins, (10) Pneu- 



PLATE CCXXXVIII. 



METOPIC 

 SUTURE. 



FRONTAL 

 %% EMINENCE 



SUPERCILIARY Wk' 

 RIDGE. 



0BICULAR1S PALPEBRARUM.' 



INT. ANGULAR PROC 



SUPRAORBITAL 

 NOTCH OR FORAMEN. 



CORRUGATOR SUPERCILII. 



NASAL SPINE. 



Extern \i. Surface of Frontal Bone. 



mogastric nerve, (11) Cardiac nerves, (12) hoop from the sympathetic. 



Behind. (1) Recurrent laryngeal nerve, (2) Sympathetic, (3) Pleura 

 i 1 1 Apex of lung. 



Beneath.— (1) Pleura, (2) Recurrent laryngeal nerve. 



Tin: Relations of First Portion ok Left Subclavian Artery. 



In Front. (1) Pneumogastric nerve, (2) Cardiac nerves, (3) Phrenie 

 nerve, (4) Left carotid artery. (5) Thoracic duct, ((i) Left internal jugular. 

 (7i Vertebral vein, (8) Innominate vein, (9) Sterno-thyroid. (10) Sterno- 

 hyoid, (11) Sterno-mastoid. 



Behind. (1) Oesophagus, (2) Thoracic duct. (.'-!) Inferior cervical gang- 



