THE TEMPORO-MAXILLARY VEIN. ^ 515 



(d) Two or three inferior palpebral veins pass inwards and downwards from the 

 lower eyelid and adjacent part of the cheek to join the facial vein below the orbifc. 

 A communication is formed between these branches and the infraorbital vein. 



(e) The superior labial vein forms a close plexus in the substance of the orbicu- 

 laris muscle in the upper lip and ascends to open into the facial vein on a level with 

 the ala of the nose. From a similar plexus in the lower lip two or three vessels 

 descend over the base of the inferior maxilla, and join the submental branch of the 

 facial or the commencement of the anterior jugular vein. 



(/) The deep facial or anterior internal maxillary vein is a vessel oLconsiderable 

 size, which passes from the pterygoid plexus downwards and forwards over the 

 zygomatic surface of the superior maxilla to open into the facial vein below the 

 malar bone. 



(ff) Small buccal, masseteric, and parotid branches also join the facial vein on its 

 outer side. 



(h) The submental vein commences below the chin, where it communicates with 

 the anterior jugular vein, and passes backwards under cover of the base of the lower 

 jaw, receiving branches from the muscles and the submaxillary gland, to join the 

 facial vein. 



(i) Submaxillary branches from the gland of that name join the facial vein 

 either separately or in common with the submental vein. 



(/) The inferior palatine vein returns the blood from a plexus surrounding the 

 tonsil and from the soft palate ; it passes downwards, being deeply seated by the 

 side of the pharynx, to join one of the preceding, or terminate separately in the 

 facial vein. 



The temporo-maxillary vein (posterior facial) is a short trunk, often pre- 

 senting a plexif orm disposition, which is formed by the union of the temporal and 

 internal maxillary veins opposite the neck of the lower jaw. It descends, embedded 

 in the substance of the parotid gland, on the outer surface of the external carotid 

 artery to near the angle of the jaw, where it divides into two parts, the one of which 

 inclines forwards, passing either over or under the stylo-hyoid and digastric muscles, 

 to join the facial vein, while the other is directed backwards across the border of the 

 sterno-mastoid muscle to form with the posterior auricular the commencement of the 

 external jugular vein. 



The temporal vein is formed close to the zygoma by the union of two vessels 

 which are known as the superficial and middle temporal veins. The superficial 

 temporal vein takes its origin in branches which spread over the top and side of the 

 head, communicating with one another, with the corresponding vessels of the oppo- 

 site side, with the frontal vein anteriorly, and with the occipital and posterior 

 auricular veins behind, so as to form a wide-meshed plexus in the subcutaneous 

 tissue. Descending over the temporal fascia, the branches are collected into two 

 vessels corresponding to, although not closely accompanying, the divisions of the 

 artery, superficial to which they are placed ; and these, joining in front of the ear, 

 give rise to the superficial trunk. The middle temporal vein is derived from a plexus 

 in the temporal fossa, from which the deep temporal veins (passing to the pterygoid 

 plexus) also issue, and piercing the temporal fascia near the zygoma unites with the 

 superficial vein. The middle temporal vein is joined by a considerable orbital 

 branch, which, after receiving some external palpebral veins from the eyelids, and 

 communicating with the supraorbital and facial veins, passes backwards with the 

 artery of the same name between the layers of the temporal fascia. The common 

 temporal vein descends over the base of the zygoma, and sinks beneath the parotid 

 gland to form by its junction with the internal maxillary vein the temporo-maxillary 

 trunk. Other tributaries of the temporal vein are the anterior auricular veins from 

 the external ear ; branches from a plexus which surrounds the articulation of the 



VOL. II. L L 



