THE ANTERIOR PART OF THE NECK 155 



branches to the pharynx and larynx, and then descends along 

 the posterior border of the thyreoid gland, distributing 

 branches to its substance and to the trachea and the 

 oesophagus. 



The following branches will be noticed arising from the 

 inferior thyreoid artery : 



1. Ascending cervical. 



2. Inferior laryngeal. 



3. Tracheal. 



5. CEsophageal. 



6. Glandular. 



7. Muscular. 



4. Pharyngeal. 



Arteria Cervicalis Ascendens. The ascending cervical artery 

 (Fig. 5 i) is a small but constant vessel which runs upwards, in 

 the interval between the scalenus anterior and longus capitis, 

 and gives branches to the muscles in front of the vertebral 

 column. It also gives off spinal branches, which enter the 

 vertebral canal upon the spinal nerves, and anastomose with 

 branches from the vertebral artery. The ultimate distribu- 

 tion of the spinal branches has been noticed already (p. 79). 



Arteria Laryngea Inferior. The inferior laryngeal artery is 

 a small vessel which accompanies the recurrent nerve to the 

 larynx. 



The trachea^ otsophageal, 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 corresponding 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 

 neighbouring muscles. 



Ventz Thyreoidetz Inferior es. The inferior thyreoid veins do 

 not run in company with the arteries of the same name. Each 

 is a comparatively large vessel which comes from the corre- 

 sponding 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 innominate vein. In other cases, however, the 

 right vein opens separately into the angle of union between 

 the two innominate veins. Both veins, as they proceed 



