THE SUPERIOR CAVAL SYSTEM. 865 



« 



The facial vein is said to be less flaccid than most superficial veins, and there- 

 fore to remain more patent after section ; it possesses either imperfectly developed 

 or rudimentary valves, or none at all. As a consequence of these facts, septic dis- 

 ease — malignant pustule, furuncle, carbuncle, cancrum oris — involving the face or 

 forehead, is exceptionally dangerous, as the infection may spread by way of the 

 ophthalmic vein or the pterygoid plexus to the cavernous sinus and result in a fatal 

 thrombosis or meningitis. 



The relations existing between the venous blood of the face and that of the 

 brain-case are rendered evident by the fact that the state of the circulation of the 

 external nose is sometimes an index of the condition of the vessels of the brain. 

 Moreover, in cases of orbital or intracranial tumors, the ophthalmic, angular, and 

 facial veins become congested, dilated, and tortuous from pressure-interference with 

 the venous current. 



The line of the facial vein is from the canthus of the eye to a point on the mandible 

 at the anterior border of the masseter muscle and just behind the facial artery. This 

 line is straight instead of tortuous, as is the case with that of the latter vessel. 



Tributaries. — The tributaries of the facial vein are (a) ihe frontal and. (d) the supraorbital, 

 by the union of which it is formed, hi addition it receives in its course across the face (r) the 

 palpebral, id) the lateral nasals, [e) the superior labial, [/) the inferior labial, [g) the deep 

 facial, ( h ) the tnasseteric, and (/' ) the anterior parotid veins. In its cerv'ical portion it has open- 

 ing into it (y ) the inferior or descendirig palatine, and [k) the subtnental wems. 



{a ) The frontal veins ( vv. fron tales) descend over the forehead on either side of the median 

 line, lying immediately beneath the skin upon the frontalis muscle. The branches from which 

 they take origin communicate at the sides and vertex of the skull with tributaries of the occip- 

 ital and temporal vefns, and also through small foramina in the frontal bone with the superior 

 longitudinal sinus. The two veins are connected by numerous cross-branches, and not infre- 

 quently unite more or less completely to form a single median stem which bifurcates below. 

 Each vein terminates at the inner angle of the orbit by uniting with the corresponding supraor- 

 bital vein to form the angular. 



At the root of the nose the two veins are usually united by a distinct cross-branch, the 

 nasal arch, which receives from below the dorsal nasal veins. 



[b) The supraorbital vein (v. supraorbitalis) is a relatively large trunk which runs trans- 

 versely above the superior margin of the orbit and consequently is quite distinct from the artery 

 of the same name. It arises at the external angle of the orbit, where it communicates with 

 affluents of the temporal veins, and passes inward beneath the orbicularis palpebrarum, and, 

 piercing that muscle just above the inner angle of the orbit, unites with the frontal vein to form 

 the angular. 



It receives numerous small branches from neighboring regions and from the diploic vein 

 of the frontal bone, and at the supraorbital notch it communicates with the ophthalmic system 

 of veins. 



{c) The palpebral veins (vv. palpebrales superiores et inferiores) are small vessels which take 

 Jieir origin from the venous plexus of the eyelids and open into the angular vein. The palpe- 

 bral plexus also communicates laterally with the affluents of the temporal veins. 



{d) The lateral nasal veins (vv. nasales externae) arise in a rich plexus which occupies the 

 alse and tip of the nose and with which the dorsal nasal vein communicates and also branches from 

 the extensive pituitary plexus, these latter branches emerging along the line of junction of the 

 nasal bones and cartilage. The veins extend upward and backward and open into the lower 

 part of the angular vein. 



{e) The superior labial or coronary vein (v. labialis superior) takes its origin in a plexus in 

 the substance of the upper lip with which branches from the septum and ala; of the nose com- 

 municate. The course of the vein is independent of that of the artery of the same name, passing 

 backward and somewhat upward to the naso-labial groove, and opening into the facial vein 

 about opposite the ala of the nose. 



(y") The inferior labial vein (v. labialis inferior) arises from a venous plexus in the lower lip 

 and passes downward and outward to open into the facial just after it has crossed the ramus of the 

 mandible. Usually a second vein, the inferior coronaiy, also arises from the inferior labial plexus 

 and passes almost horizontally outward to open into the facial a little below the angle of the mouth. 



{g) The deep facial vein, also termed the ante^-ior internal maxillary , takes its origin from 

 the pterygoid plexus (page8S2) over the tuberosity of the maxilla, through which it receives 

 branches from a net-work lying beneath the mucous membrane lining the antrum of Highmore. 

 It passes forward and downward between the buccinator and masseter muscles, and opens into 

 the outer surface of the facial where that vein passes beneath the zygomatic muscle. 



55 



