THE HEAD AND NECK. 67 



remove the pleura. The artery gives off its deep cervical branch, which inos- 

 culates with the arteria princcps cervicis, a branch of the occipital. The anasto- 

 mosis takes place between the complexus and semispinalis colli muscles. By 



Right anterior cerebral 



Internal carotid 

 Right posterior cerebral 



Occipital 

 Princeps cervicis 



External carotid 



Superficial branch of princeps cervicis 

 Deep branch 



Ascending cervical 



Transverse cerrinil 

 Posterior scapular 

 Acromial branch 

 Subscapular brunch ,- 



Supraspinous ^ 



branch 



Anterior circumflex 

 Infraspimrtii 



branch 



Posterior circumflex 



Long thoracic 



Subicapulai 



Dorsal scapular 

 fnfraieapttlar 



Subscapular 



Left anterior cerebral 

 Anterior cotlMnunicutilig 



Posterior comma n icatiny 

 Left posterior cerebral 



Basilar 



Anterior spinal 



Superior thyroid 



Inferinr (lit/mid 



Common carotid 



Thyroid axis 

 Superior inten-ostai 



Illin>ltliliat<! 



'<>! intrrriis'iil 

 I.H't ennnnon carotid 

 LfJ't subclavinn 

 tjhiirt thoracic 



lii/ernal mammary 



Anterior intercostal 



I-'irxt aortic inter- 

 costal 



Second aor/ic inter- 

 com tal 



A n lerior in tcrcosla I 



Third aortic inter- 

 costal 



FIG. 38. THE COLLATERAL CIRCULATION AFTER LIGATURE OF THE COMMON CAROTID AND 



Si ix I.AVIAN ARTERIES. 

 (A ligature is placed on the common carotid and on the third portion of the subclavian artery.) 



this anastomosis the collateral circulation is carried on after ligature of the 

 common carotid artery. (Figs. 38, 39, and 40.) 



The vertebral artery (Fig. 40) is given off from the second stage of the 



