CAROTID ARTERY. 



487 



the facial artery continues its course upwards 

 and inwards, and, opposite the commissure 

 of the lips, gives oft' d, the superior labial 

 coronary artery. This vessel passes inwards 

 among the fibres of the orbicularis oris, runs 

 above the free border of the upper lip nearer 

 to its mucous membrane than to its cutaneous 

 surface, gives branches to the various parts 

 composing the upper lip, and meets the co- 

 ronary of the opposite side, with which it 

 very freely anastomoses. The superior labial 

 coronary always sends off from the place 

 where it anastomoses with that of the opposite 

 side a branch, which ascends towards the 

 septum of the nose, and which is called the 

 artery of the septum of the nose, (arteria 

 septi nasi.) The place of this artery is some- 

 times occupied by two or more branches ; it 

 divides, near the septum of the nose, into 

 at least two branches, which pass, one on either 

 side, along the inferior border of the septum 

 to the extremity of the nose, where it anasto- 

 moses with branches of the lateral nasal : 

 sometimes the superior coronary gives off a 

 branch (ramuspinnalis), as it passes the ala 

 of the nose, to which, and the external part 

 of the nostril, it is distributed. 



After the origin of the superior labial the 

 facial artery is reduced to a very small size, 

 and its continuation is by some called the 

 external nasal, arteria nasalis externa coin- 

 munis. It continues to pass obliquely up- 

 wards, forwards, and inwards under the levator 

 labii superioris, to which it gives branches : 

 after anastomosing with the infra-orbital artery 

 and giving oft' branches, which pass forward 

 on the lateral surface of the nose, namely, e, 

 laterales nasi, andy, dorsales nasi, which freely 

 anastomose with each other, with the artery of 

 the septum, and those of the opposite side 

 on the dorsum of the nose, it emerges from 

 between the two heads of the levator labii 

 superioris, and becoming subcutaneous, ter- 

 minates at the inner canthus of the eye by 

 anastomosing with the termination of the nasal 

 branch of the ophthalmic, at which place it has 

 received the name of the angular artery. 



Irregularities of the labial or facial artery. 

 It sometimes happens that the facial artery is 

 smaller than usual, and terminates at the angle 

 of the mouth or even below the situation of 

 the usual origin of the inferior coronary ; in 

 this case the transverse facial branch of the 

 temporal generally fnrnishes the branches which 

 the coronary has failed to produce ; on the 

 other hand the labial artery is sometimes of a 

 larger size than usual, as happens when it 

 furnishes supernumerary branches, such as the 

 ranine or sublingual. The facial artery is the 

 principal source of communication between the 

 superficial and deep branches of the external 

 carotid by its anastomoses with the infra-orbital, 

 nasal and dental arteries ; and of the external 

 carotid with the internal, by its anastomoses 

 with the ophthalmic. 



Internal branch of the external carotid, 

 Inferior pharyngeal arten/, (a. pharyngea in- 

 ferior v. (iscendens,) arises commonly from the 

 internal side of the external carotid close to its 



origin, sometimes from the bifurcation of the 

 primitive carotid, more rarely from the internal 

 carotid, and occasionally from the occipital; 

 sometimes its place is supplied by the inferior 

 palatine or by branches from the trunk of the 

 facial ; sometimes it is double, in which case 

 only one of its branches arises from the external 

 carotid, the other being furnished by one of 

 the smaller arteries already mentioned, or by 

 the internal carotid ; this artery is always the 

 smallest branch of the external carotid; it 

 passes perpendicularly upwards internal to the 

 externa! carotid between the trunk of that 

 vessel and the pharynx, lying on the rectus 

 capitis anticus major muscle, and closely re- 

 lated to the superior cervical ganglion of the 

 sympathetic. Having furnished branches from 

 its inner side, both ascending and descending, 

 to the constrictors of the pharynx and other 

 muscles, which also supply the mucous mem- 

 brane, and from its external side to the deep 

 muscles of the neck, it terminates at the basis 

 cranii, near the petrous portion of the temporal 

 bone, by giving oft' its terminal branches, of 

 which one, the proper pharyngeal, is princi- 

 pally distributed to the parietes of the pharynx, 

 and communicates by anastomosis with the 

 inferior palatine from the superior thyroid ; a 

 second, the posterior meningeal artery, enters 

 the cranium by the foramen lacerum posterius, 

 or by an opening in the vicinity of the condyle 

 of the occipital bone, and is distributed to the 

 dura mater lining the inferior occipital fossa : 

 and a third ascends to the basis cranii, and per- 

 forates the cartilaginous lamella, which fills up 

 the foramen lacerum posterius, to enter the 

 cranium and be distributed to the dura mater. 



POSTERIOR BRANCHES OF THE EXTERNAL 

 CAROTID. 1st. The occipital artery (a. occi- 

 pilalis) arises from the posterior side of the 

 external carotid, opposite the lingual or the 

 facial ; it sometimes but rarely comes from the 

 internal carotid ; it passes at first a little ob- 

 liquely backwards along the lower border of 

 the posterior belly of the digastric muscle 

 which overlaps it; it crosses over the ninth pair 

 of nerves which winds beneath it just at its 

 origin, the internal carotid artery, internal 

 jugular vein, and spinal accessory nerve ; and 

 passing backwards between the transverse pro- 

 cess of the atlas and the mastoid process of 

 the temporal bone it is lodged in a groove in 

 this latter bone, which is internal to the inser- 

 tion of the posterior belly of the digastric ; it 

 crosses the outer border of the rectus capitis 

 lateralis muscle, and continuing its course 

 beneath the sterno-cleido-mastoid, trachelo- 

 mastoid, splenius capitis and trapezius, and 

 over the obliquus superior and complexus, it 

 ascends tortuously over the superior part of the 

 occipital bone, where it becomes cutaneous 

 and anastomoses with branches from the tem- 

 poral, posterior auris, and opposite occipital. 

 The first branches of the occipital are small, 

 and are distributed to the sterno-mastoid, di- 

 gastric, and stylo-hyoid muscles, and to the 

 lymphatic glands in the neighbourhood ; the 

 branches which enter the sterno-mastoid are 

 sometimes considerable, and anastomose freely 



