THE ANTERIOR PART OF THE NECK 253 



anastomose with branches from the vertebral artery. The 

 ultimate distribution of the spinal branches has been noticed 

 already (p. 193). 



Arteria Laryngea Inferior. This small vessel accompanies 

 the inferior laryngeal nerve to the larynx. The trachea!, asopha- 

 geal, and pharyngeal branches supply the trachea, the gullet, 

 and the pharynx. They are of small size, and anastomose 

 with the bronchial and cesophageal branches of the thoracic 

 aorta. The glandular branches are usually two in number. 

 One ascends upon the posterior aspect of the lateral lobe of 

 the thyreoid gland, whilst the other is given to its base or 

 lower end. They inosculate with the corresponding vessels 

 of the opposite side, and also with the branches of the 

 superior thyreoid artery. The muscular branches are a series 

 of irregular twigs given to the various muscles in the 

 neighbourhood. 



Vena Thyreoidea Inferior. The inferior thyreoid vein does 

 not run in company with the artery of the same name. It is a 

 comparatively large vessel which comes from the lateral lobe 

 and the isthmus of the thyreoid gland, and descends upon 

 the trachea under cover of the sterno-thyreoid muscle. The 

 veins of both sides enter the thorax, and frequently unite to 

 form a short common stem, which opens into the left in- 

 nominate trunk. In other cases, however, the right vein 

 will be observed to open separately into the angle of union 

 between the two innominate veins. Both veins, as they 

 proceed 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. 



The Transverse Scapular and Transverse Cervical Arteries. 

 Both of these arteries have already been examined in the 

 greater part of their courses (p. 147). 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. 



