THE I/EINS. 323 



V. facialis profunda (Fig. 131, //). The deep facial vein 

 enters the anterior facial from beneath the masseter, just caudad 

 of the angle of the mouth. It collects branches from the soft 

 and hard palates and the teeth, these branches passing along 

 with the corresponding arteries for a distance, then uniting and 

 passing ventrolaterad beneath the zygomatic arch to join the 

 anterior facial. The deep facial vein also receives branches 

 which come from the venous plexus that lies in the same region 

 as the arterial carotid plexus. 



V. submentalis (Fig. 131, /). This enters the anterior 

 facial vein at the ventral border of the masseter muscle and 

 near the cranial end of the two superficial lymph-glands (12) 

 in this region. The submental vein is formed at the dorsal 

 border of the digastric muscle by two branches emerging from 

 between the digastric and the mandible. The more cranial 

 of these, V. lingualis, collects branches from the tongue, 

 from its middle to the tip; it passes through the middle of the 

 lateral border of the mylohyoid muscle to join the other branch. 

 The second branch emerges from between the mandible and 

 the pterygoid muscles. It comes from near the caudal end of 

 the mandible, where it becomes continuous with a communi- 

 cating branch from the posterior facial vein, and receives a 

 branch which comes from the mandibular canal ; also small 

 branches from the adjacent parts. 



e. V. facialis posterior (Fig. 131, b}. The posterior facial 

 vein arises from the region of the internal maxillary artery, its 

 terminal branches following the branches of the artery. It 

 collects blood from the pterygoid, masseter (9), and temporal 

 muscles, and forms a plexus which is interwoven with the 

 carotid (arterial) plexus in the region of the orbital fissure. It 

 is connected with the submental vein by a communicating 

 branch. From the posterior facial a branch extends ventrad 

 close against the outer surface of the tympanic bulla and then 

 turns caudad, receives a branch from the pharynx, then con- 

 tinues to join the internal jugular. The posterior facial itself 

 passes laterad along the caudal border of the masseter (9) and 

 the ventral border of the parotid gland (10), then becomes 

 superficial and turns ventrad over the outer surface of the sub- 



