THE VEINS OF THE NECK 



649 



vein), a branch of considerable size, begins below the tip of the tongue, and may 

 join the lingual; generally, however, it passes backward on the Hyoglossus, and 

 joins the common facial. 



The Pharyngeal Veins (w. pharyngece) begin in the pharyngeal plexus on the outer 

 surface of the pharynx, and, after receiving some posterior meningeal veins and the 

 vein of the pterygoid canal, end in the internal jugular. They occasionally open 

 into the facial, lingual, or superior thyroid vein. 



The Superior Thyroid Vein (v. thyreoidea superioris) (Fig. 560) begins in the sub- 

 stance and on the surface of the thyroid gland, by tributaries corresponding with 

 the branches of the superior thyroid artery, and ends in the upper part of the 

 internal jugular vein. It receives the superior laryngeal and cricothyroid veins. 



The Middle Thyroid Vein (Figs. 561, 562) collects the blood from the lower part 

 of the thyroid gland, and after being joined by some veins from the larynx and 

 trachea, ends in the lower part of the internal jugular vein. 



The common facial and occipital veins have been described. 



External carotid artery 



Superior thyroid artery 

 Superior thyroid vein 



Middle thyroid vein 





Fia. 560. The veins of the thyroid gland. 



The vertebral vein (v. vertebralis) is formed in the suboccipital triangle, from 

 numerous small tributaries which spring from the internal vertebral venous plexuses 

 and issue from the vertebral canal above the posterior arch of the atlas. They 

 unite with small veins from the deep muscles at the upper part of the back of 

 the neck, and form a vessel which enters the foramen in the transverse process 

 of the atlas, and descends, forming a dense plexus around the vertebral artery, 

 in the canal formed by the foramina trans versaria of the cervical vertebrae. This 

 plexus ends in a single trunk, which emerges from the foramen transversarium of 

 the sixth cervical vertebra, and opens at the root of the neck into the back part 

 of the innominate vein near its origin, its mouth being guarded by a pair of valves. 

 On the right side, it crosses the first part of the subclavian artery. 



