486 



CAROTID ARTERY. 



artery sends off the following branches, a, 

 The hyoidean branch, arising at the external 

 edge of the hyoglossus muscle, passes be- 

 tween the genio-hyoideus and genio-glossus, 

 and coming forward in the mesial line, de- 

 scends over the front of the body of the os 

 hyoides, and anastomoses with the hyoidean 

 branch of the thyroid artery, giving branches 

 to the muscles, in the vicinity of which it 

 passes and to the integuments. b y The dorsalis 

 lingua, arising under cover of the hyoglossus, 

 passes upwards and outwards, crossing the 

 stylo-glossus and distributes its branches over 

 the posterior part of the dorsum of the tongue, 

 the tonsils, velum palati, and epiglottis, where 

 it anastomoses with the laryngeal branch of 

 the superior thyroid. At the internal edge 

 of the hyoglossus the lingual artery divides 

 into the sublingual and ranine. c, The sub- 

 lingual branch passes forwards between the 

 mylo-hyoid and genio-glossus muscles and 

 above the sublingual gland, to which it is 

 principally distributed, as well as to the 

 muscles of the tongue and the mucous mem- 

 brane of the mouth. Occasionally we find 

 the place of the sublingual artery supplied by 

 the submental, a branch of the facial, d, The 

 ranine artery, which is the continuation of the 

 trunk of the lingual, passes forward between the 

 genio-glossus and lingualis, and running along 

 the under surface of the tongue by the side 

 of the attachment of the frsenum, sends nu- 

 merous branches into the substance of that 

 organ, and ends by anastomosing with the 

 ranine of the opposite side. It is this artery 

 which is endangered if the scissors be directed 

 too much upwards in dividing the fraenum 

 linguae in children. 



3. The labial artery, called also facial or 

 external maxillary, (a. facialis v. maxillaris 

 externa,) varies very much in its origin, size, 

 and the extent of its distribution. It is usually 

 the largest of the three anterior branches of 

 the external carotid, and supplies the whole 

 of the anterior part of the face ; sometimes, 

 however, it only extends as far as the angle 

 of the mouth, beyond which its place is 

 supplied by the temporal artery. There is, 

 perhaps, no other artery which presents so 

 many varieties, even on opposite sides of the 

 body in the same subject. From its origin 

 it proceeds, in a tortuous course, inwards 

 and forwards, towards the internal part of the 

 angle of the lower jaw, covered by the hypo- 

 glossal nerve, the digastric and stylo-hyoid 

 muscles : it then passes between the lower 

 jaw and submaxillary gland, lodged in a 

 groove in that gland ; after which it turns 

 over the inferior border of the lower jaw, and 

 arrives on the external surface of that bone 

 a little in front of the anterior edge of the 

 masseter muscle : from this it ascends tor- 

 tuously towards the commissure of the lips, 

 covered by the skin and the platysma ; thence 

 passing upwards and inwards under the zygo- 

 matic muscles, and over the buccinator and 

 levator anguli oris, it continues to ascend in 

 the groove between the cheek and the upper 

 lip and by the side of the nose, to the internal 



canthus of the eye, where, very much dimi- 

 nished in size, it terminates by anastomosing 

 with the nasal branch of the ophthalmic artery. 



Branches. The branches of the labial artery 

 are very numerous. a, The inferior palatine, 

 which arises from the labial close to its origin; 

 this vessel sometimes comes from the trunk 

 of the carotid itself, it passes upwards between 

 the stylo-pharyngeus and stylo-glossus, to 

 which it gives branches : it then attaches itself 

 to the superior and lateral part of the pharynx, 

 supplying this region, the tongue, and the 

 tonsil. Having reached the velum palati, it 

 divides into many branches, which are dis- 

 tributed to the muscles, mucous membrane, 

 and glands of that organ, and to the Eustachian 

 tube. These branches anastomose with the 

 superior palatine branch of the internal max- 

 illary. The tonsillitic artery, (arteria tonsil- 

 laris of Soemmerring,) enumerated as a dis- 

 tinct branch of the labial by Professor Harrison, 

 is, more properly speaking, a branch of the 

 inferior palatine. 



In passing through the sub-maxillary gland, 

 the labial artery gives off several branches to 

 this gland, the internal pterygoid muscle, 

 and the mucous membrane of the mouth : as 

 it is about to turn over the side of the lower 

 jaw, there arises from it a branch of more 

 considerable size, namely, b, the submental 

 branch. This artery passes forwards beneath 

 the base of the lower jaw, covered by the 

 platysma and anterior belly of the digastric, 

 between which and the mylo-hyoideus it takes 

 its course towards the symphysis of the chin, 

 distributing branches to supply the muscles 

 and integuments in this region and to anasto- 

 mose with the sublingual ; some of its branches 

 mount over the chin and communicate with 

 the arteries of the lower lip : the submental 

 artery sometimes furnishes the sublingual, and 

 at other times it is given off by this latter. 



From the inferior border of the lower jaw 

 to the commissure of the lips, the labial gives 

 several branches, some of which are anterior 

 and some posterior: the posterior are com- 

 paratively insignificant branches distributed to 

 the masseter, platysma, buccinator, parotid 

 gland and duct, the cellular tissue and in- 

 teguments of the cheek, which communicate 

 with branches of the transverse facial. Besides 

 smaller branches given off anteriorly to the 

 lips, there are two considerable branches and 

 one of lesser size, which require a more par- 

 ticular description ; viz. c, the inferior labial 

 coronary arises about midway between the 

 commissure of the lips and the base of the 

 lower jaw, it passes under the triangularis oris 

 muscle, to which, as well as to the quadratus, 

 levator labii inferioris, and mucous membrane 

 of the mouth, it gives numerous branches and 

 anastomoses with its congener, and the mental 

 branch of the inferior dental. This artery is 

 sometimes smaller on one side than on the 

 other; it is sometimes absent on one side, 

 when its place is supplied by the artery of 

 the opposite side; sometimes it arises from 

 the superior labial coronary; sometimes it is 

 double. After having given off this branch, 



