THE ANTERIOR PART OF THE NECK 249 



pleura, a short distance below its summit. At the outer 

 border of the first rib it becomes the axillary artery. 



For descriptive purposes the artery is divided into three 

 parts. The first part extends from the origin of the vessel 



- Basilar artery 

 -Vertebral artery 



.Vertebral artery 



Vertebral artery 

 5th cervical vertebra 

 Scalenus anterior - 

 Transverse cervical artery' 

 Inferior thyreoid artery-" 

 Thyreo-cervical trunk- 

 Transverse scapular art. 



Superior inter- 

 costal artery 

 Right common 



carotid"/ 



Deep cervical artery 



Inferior thyreoid artery 

 ,-' Scalenus anterior 

 Transverse cervical 

 artery 



Costo-cervical trunk 

 Transverse 

 "scapular artery 

 - Superior intercostal art. 

 .Subclavian artery 

 Left subclavian 

 artery 



Left common 

 'carotid 



I nternal 



mammary 



artery 



FIG. 103.- 



-Diagram of Subclavian Arteries and their 

 branches. 



to the medial margin of the scalenus anterior; the second 

 portion lies posterior to that muscle ; and the third part 

 extends from the lateral border of the scalenus anterior to 

 the outer border of the first rib. 



First Part. Owing to the difference of origin, the relations 

 of the first portion of the subclavian artery are not the same 



