648 



ANGIOLOGY 



tion to the external jugular; most frequently there are two anterior jugulars, 

 right and left; but sometimes only one. Its tributaries are some laryngeal veins, 

 and occasionally a small thyroid vein. Just above the sternum the two anterior 

 jugular veins communicate by a transverse trunk, the venous jugular arch, which 

 receive tributaries from the inferior thyroid veins; each also communicates with the 

 internal jugular. There are no valves in this vein. 



The internal jugular vein (v. jugularis interna) collects the blood from the brain, 

 from the superficial parts of the face, and from the neck. It is directly continuous 

 with the transverse sinus, and begins in the posterior compartment of the jugular 

 foramen, at the base of the skull. At its origin it is somewhat dilated, and this 

 dilatation is called the superior bulb. It runs down the side of the neck in a vertical 

 direction, lying at first lateral to the internal carotid artery, and then lateral 

 to the common carotid, and at the root of the neck unites with the subclavian vein 

 to form the innominate vein; a little above its termination is a second dilatation, 

 the inferior bulb. Above, it lies upon the Rectus capitis lateralis, behind the internal 

 carotid artery and the nerves passing through the jugular foramen; lower down, 

 the vein and artery lie upon the same plane, the glossopharyngeal and hypoglossal 

 nerves passing forward between them; the vagus descends between and behind 

 the vein and the artery in the same sheath, and the accessory runs obliquely 

 backward, superficial or deep to the vein. At the root of the neck the right internal 

 jugular vein is placed at a little distance from the common carotid artery, and 



DORSALIS 

 LINGU/E ARTCR 

 LINGUAL VEIN 

 VEINS OF 

 DORSUM OF 

 TONGUE 



HYPOGLOSSAL NERVE 



FIG. 559. Veins of the tongue. 



The hypoglossal nerve has been displaced downward in this preparation. 

 (Testut after Hirschfeld.) 



crosses the first part of the subclavian artery, while the left internal jugular vein 

 usually overlaps the common carotid artery. The left vein is generally smaller 

 than the right, and each contains a pair of valves, which are placed about 2.5 cm. 

 above the termination of the vessel. 



Tributaries. This vein receives in its course the inferior petrosal sinus, the common 

 facial, lingual, pharyngeal, superior and middle thyroid veins, and sometimes the 

 occipital. The thoracic duct on the left side and the right lymphatic duct on the 

 right side open into the angle of union of the internal jugular and subclavian veins. 



The Inferior Petrosal Sinus (sinus petrosus inferior) leaves the skull through the 

 anterior part of the jugular foramen, and joins the superior bulb of the internal 

 jugular vein. 



The Lingual Veins (vv. ling nates') begin on the dorsum, sides, and under surface 

 of the tongue, and, passing backward along the course of the lingual artery, end 

 in the internal jugular vein. The vena comitans of the hypoglossal nerve (ranine 



