THE CIRCULATORY OR VASCULAR SYSTEM 121 



Sinuses are venous channels found chiefly within the 

 cranium. They, together with the blood-supply of the 

 cerebrum, will be considered in the chapter on the Nervous 

 System. 



VEINS OF THE HEAD AND NECK 



The veins of the exterior of the head are as follows : 



Facial. Temporomaxillary. 



Internal maxillary. Posterior auricular. 



Temporal. Occipital. 



(The student will bear in mind that the veins bear the 

 same names as the arteries, and are generally in the same 

 sheath; this is particularly true of the deep trunks.) 



The facial vein takes its commencement on the 

 anterior part of the head, from a plexus of the temporal 

 branches. Under the name frontal vein it passes along 

 the middle line of the forehead to the root of the nose, 

 where it is connected with its fellow of the opposite side 

 by a communicating branch. It is divided into several 

 branches, which are distributed about the anterior part 

 of the face; it receives, in its course, the supra-orbital, the 

 frontal vein, and the dorsal veins of the nose; also all 

 veins that correspond with the branches of the facial 

 artery. 



The internal maxillary vein joins the temporal 

 vein. 



The temporal vein drains the region of the temple and 

 enters the parotid gland, after which it unites with the 

 internal maxillary vein to form the temporomaxillary. 



The temporomaxillary vein is formed by the union 

 of the temporal and internal maxillary. It divides into 

 two branches, one joining the facial vein, and the other 

 joining with the posterior auricular to form the external 

 jugular. 



