THE SUPERIOR CAVAL SYSTEM. 



883 



by their names. It then passes between the two heads of the external pterygoid muscle and 

 opens into the pterygoid plexus or into the internal maxillary vein. 



{b) The superior dental veins open into the infra-orbital and alveolar portions of the plexus. 



(c) Muscular veins from the masseter, buccal, and pterygoid muscles. 



(d) The deep temporal veins (vv. temporales profundae) descend from the substance of the 

 temporal muscle, where they anastomose with the superficial temporals, between the muscle 

 and the bone. 



{e) The middle meningeal veins (vv. meningeae mediae) accompany the main stem and 

 branches of the middle meningeal artery as venae comites and return the blood from the dura mater 

 lining the sides and vertex of the cranium. Lying in the substance of the dura mater, these veins 



Fig. 760. 



Temporal fascia 



Supraorbital vein 



Temporal muscle 



Superficial 



temporal vein- 



Middle 



temporal vein 



Middl<. 



meningfeal vein 



Upper part of 

 pterygoid plexuS' 



Internal 



maxillary vein 



Temporal vein 



Pterygoid plexusi 



Internal pterygoid muscle 

 Temporo-maxillary veir 

 Posterior auricular vein 



Posterior trunk of 



temporo-maxillary vein 

 interior trunk of 



temporo-maxillary vein' 



Sterno-cleido-mastoid muscle' 



External jugular vein 



Internal carotid artery 



Internal jugular vein 



Frontal veins 



Angular vein 



Communicating 

 branch to 

 ophthalmic 



One of deep 



temporal vein* 



External 



pterygoid muscle 



Buccal vein 



Deep facial vein 

 Inferior dental vein 



Facial vein 



Submental vein 



Submaxillary gland 



Inferior palatine vein 

 Lingual vein 



ommon facial vein 



onimunicating branch to 



anterior juguLir vein 



Common carotid artery 



Veins of head ; part of mandible and associated muscles have been removed 



to expose pterygoid plexus. 



resemble the sinuses of the dura in their structure, and they communicate with the blood-lakes of 

 the dura, with the superior longitudinal, spheno-parietal and petro-squamosal sinuses, and with 

 the superficial Sylvian vein. They open below into the deeper portion of the pterygoid plexus, 

 (_/) The inferior dental vein follows the course of the inferior dental artery, opening abo\'e 

 into the more superficial portion of the plexus. 



2. The Posterior Auricular Vein. — The posterior auricular vein (v. auricularis 

 posterior) arises from a plexus situated over the mastoid portion of the temporal bone 

 and communicating with branches of the occipital and temporal veins. It descends 



