i 5 6 HEAD AND NECK 



downwards, receive tributaries from the larynx, trachea and 

 oesophagus. 



The anterior vertebral vein accompanies the ascending 

 cervical artery, and opens into the vertebral vein as it issues 

 from the foramen transversarium of the sixth cervical vertebra. 



Arteriae Transversse Scapulae et Colli. The transverse 

 scapular and the transverse cervical arteries have already 

 been examined in the greater part of their courses (p. 34). 

 After taking origin from the thyreo-cervical trunk, they both 

 pass laterally, across the scalenus anterior muscle and the 

 phrenic nerve, under cover of the clavicular head of the 

 sterno-mastoid. The transverse scapular crosses the anterior 

 scalene muscle close to its insertion, immediately above the 

 subclavian vein ; the transverse cervical is placed at a slightly 

 higher level. 



The transverse scapular and transverse cervical veins have 

 already been seen joining the external jugular vein (p. 40), 



Arteria Mammalia Interna. The internal mammary artery 

 springs from the lower and anterior aspect of the subclavian, 

 directly below the thyreo-cervical trunk. It passes downwards 

 to reach the thorax, lying upon the anterior surface of the 

 pleura, and posterior to the medial end of the clavicle and 

 the medial end of the subclavian vein. As it lies posterior 

 to the subclavian vein the phrenic nerve passes from its 

 lateral to its medial side, either anterior or posterior to it. 

 In the neck the internal mammary artery is not accompanied 

 by a vein. 



Truncus Costocervicalis. On the right side the costo- 

 cervical trunk takes origin from the posterior aspect of the 

 second portion of the subclavian artery, close to the medial 

 border of the scalenus anterior. To bring it into view the 

 subclavian artery must be dislodged from its position. On 

 the left side, however, it proceeds, as a rule, from the first 

 part of the parent trunk. It is a short trunk which passes 

 upwards and backwards, over the apex of the pleura, to the 

 neck of the first rib, where it divides into the deep cervical 

 artery and the superior intercostal artery. 



If the lung is removed from the thorax, the dissector 

 should take the opportunity of examining this artery from the 

 thoracic aspect. 



Arteria Cervicalis Profunda. The deep cervical artery 

 passes dorsally, and disappears from view between the 



