596 THE BLOOD-VASCULAR SYSTEM. 



establishing an important anastomosis between this vessel and the cavernous sinus. 

 Some small veins from the dorsuni of the nose terminate in the nasal arch. 



The Facial Vein commences at the side of the root of the nose, being a direct 

 continuation of the angular vein. It lies behind and follows a less tortuous 

 course than the facial artery. It passes obliquely downward and outward, 

 beneath the Zygomaticus major and minor muscles, descends along the anterior 

 border of the Masseter, crosses over the body of the lower jaw, with the facial 

 artery, and, passing obliquely outward and backward, beneath the Platysma 

 and cervical fascia, unites with the anterior division of the temporo-maxillary vein, 

 to form a trunk of large size (common facial vein), which enters the internal 

 jugular. From near its termination a communicating branch often runs down the 

 anterior border of the Sterno-mastoid to join the lower part of the anterior jugular. 



Tributaries. The facial vein receives, near the angle of the mouth, communi- 

 cating tributaries of considerable size (the deep facial or anterior internal maxil- 

 lary vein) from the pterygoid plexus. It is also joined by the inferior palpebral, 

 the superior and inferior labial veins, the buccal veins from the cheek, and the 

 masseteric veins. Below the jaw it receives the submental; the inferior palatine, 

 which returns the blood from the plexus around the tonsil and soft palate ; the 

 submaxillary vein, which commences in the submaxillary gland ; and, generally, 

 the ranine vein. 



Surgical Anatomy. There are some points about the facial vein which render it of great 

 importance in surgery. It is not so flaccid as are most superficial veins, and, in consequence of 

 this, remains more patent when divided. It has, moreover, no valves. It communicates freely 

 with the intracranial circulation, not only at its commencement by its tributaries, the angular 

 and supra-orbital veins, communicating with the ophthalmic vein, a tributary of the cavernous 

 sinus, but also by its deep branch, which communicates through the pterygoid plexus with the 

 cavernous sinus by branches which pass through the foramen ovale and foramen lacerum 

 medium (see pasre 606). These facts have an important bearing upon the surgery of some 

 diseases of the face, for on account of its patency the facial vein favors septic absorption, and 

 therefore any phlegmonous inflammation of the lace following a poisoned wound is liable to set. 

 up thrombosis in the facial vein, and detached portions of the clot may give rise to purulent 

 foci in other parts of the body. And on account of its communications with the cerebral sinuses 

 these thrombi are apt to extend upward into them and so induce a false issue. 



The Temporal Vein commences by a minute plexus on the side and vertex of 

 the skull, which communicates with the frontal and supra-orbital veins in front, 

 the corresponding vein of the opposite side, and the posterior auricular and 

 occipital veins behind. From this network anterior and posterior branches are 

 formed which unite above the zygoma, forming the trunk of the vein. This 

 trunk is joined in this situation by a large vein, the middle temporal, which 

 receives the blood from the substance of the Temporal muscle and pierces the 

 fascia at the upper border of the zygoma. The temporal vein then descends 

 between the external auditory meatus and the condyle of the jaw, enters the sub- 

 stance of the parotid gland, and unites with the internal maxillary vein to form 

 the temporo-maxillary vein. 



Tributaries. The temporal vein receives in its course some parotid veins, an 

 articular branch from the articulation of the jaw, anterior auricular veins from 

 the external ear, and a vein of large size, the transverse facial, from the side of 

 the face. The middle temporal vein, previous to its junction with the temporal 

 vein, receives a branch, the orbital vein, Avhich is formed by some external palpe- 

 bral branches, and passes backward between the layers of the temporal fascia. 



The Internal Maxillary Vein is a vessel of considerable size, receiving branches 

 which correspond with those of the internal maxillary artery. Thus it receives 

 the middle meningeal veins, the deep temporal, the pterygoid, masseteric, buccal, 

 alveolar, some palatine veins, and the inferior dental. These branches form a 

 large plexus, the pterygoid, which is placed between the Temporal and External 

 pterygoid and partly between the Pterygoid muscles. This plexus communicates 

 very freely with the facial vein and with the cavernous sinus by branches through 

 the foramen Vesalii, foramen ovale, and foramen lacerum medium, at the base of 



