THE COMMON CAROTID ARTERIES. 



389 



thyroid muscles ; it is covered in front by the remains of the thynms gland, and is 

 crossed by the left innominate vein. This part of the artery lies at first over the 

 trachea, and then over the oesophagus and thoracic duct. The pneumo-gastric 



Fig. 335. VIEW OP THE RIGHT COMMON CAROTID AND SUBCLAVIAN ARTERIES, WITH THE ORIGIN 



OP THEIR BRANCHES AND THEIR RELATIONS. (R. Quain.) 



The sterno-mastoid, sterno-thyroid, sterno-hyoid, and omo-hyoid muscles have been in great part 

 removed, the trapezius has been detached from the outer part of the clavicle and turned backwards, and 

 the inner part of the clavicle has been removed, a, parotid gland near the place where the duct leaves 

 it ; b, angle of the jaw and masseter muscle ; c, submaxillary gland ; d, upper part of sterno-mastoid ; 

 e, hyoid bone ; /, thyroid cartilage ; g, thyroid body ; h, trachea ; i, i', sawn ends of the clavicle, the 

 portion between them having been removed ; k, first rib ; Z, sternum ; m, scalenus medius ; n, levator 

 anguli scapulae ; o, trapezius ; p, on the rectus anticus major muscle, points to the pneumo-gastric 

 nerve ; IV, uppermost of the nerves of the brachial plexus ; A, innominate artery ; 1, right common 

 carotid ; 2, internal carotid ; 2', upper part of the internal jugular vein, which has been removed 

 between 2', and i ; 3, and 4, external carotid ; 3 is placed at the origin of the superior thyroid artery ; 

 4, at that of the lingual ; farther up the vessel may be seen the separation of the sterno-mastoid twig 

 and the facial and occipital branches from the main vessel ; 5, is placed on the thyro-hyoid muscle 

 between the hyoid and laryngeal branches of 5', the superior thyroid artery ; 6, facial artery, passing 

 over the base of the jaw ; 7, superficial temporal artery ; 8, first part, 8', third part of subclavian 

 artery ; 8", subclavian vein separated from the artery by the scalenus anticus ; 9, is placed on the 

 scalenus anticus in the angle between the superficial cervical and suprascapular branches of the thyroid 

 axis ; 10. outer part of suprascapular artery ; 10', superficial cervical artery ; 10", posterior scapular 

 artery ; 11, on the scalenus anticus, points to the inferior thyroid artery near the place where the 

 ascending cervical artery is given off ; the phrenic nerve lies on the muscle to the outside of the figure ; 

 at i, the suprasternal twig of the suprascapular artery is shown. 



c c 2 



