496 THE ARTERIES 



lowintj l»ranches: — ((OAntral, which }iass through small foramina into the antrum; 

 (//) dental, whic-li ])a<s into hony canals to sui)])ly the molar and l)icusi)id teeth; 

 {c) alveolar, uv gingival, which supi)ly the gums; and ((/) buccal, which are tlis- 

 tributecl to the buccinator muscle. 



(2) The infraorbital branch arises from the internal maxillary, generally as a 

 common trunk with the posterior dental. It passes forwards and a little upwards 

 through the spheno-maxillary fossa; then forwards in company Avith the maxillary 

 division of the fifth nerve, first along the groove, and then through the canal in the 

 orbital plate of the maxilla; and finally, emerging on the face at the infraorl)ital 

 foramen, under cover of the levator labii superioris proprius, is distriljuted to the 

 structures forming the upper lip, the lower eyelid, the lachrymal sac, and the side 

 of the nose. It anastomoses with the superior coronary and angular l^ranches of 

 the facial, Avith the nasal and lachrymal branches of the ophthalmic, and with the 

 transverse facial. It gives off the following small branches: — (a) Orbital, to the 

 fat of the orbit and to the inferior rectus and inferior obliciue muscles; (6) an 

 anterior dental branch, which passes downwards through a groove in the anterior 

 Avail of the superior maxilla, together Avith the anterior dental branch of the infra- 

 orbital nerve, and, supplies branches to the incisor and canine teeth and the mucous 

 membrane of the antrum; and (c) nasal branches, Avhich pass through the 

 foramina in the nasal process of the superior maxilla (sutura notha). 



(3) The posterior or descending palatine branch descends in the posterior 

 palatine canal Avith the great or anterior palatine branch of Meckel's ganglion. On 

 emerging on the palate at the posterior palatine foramen, it divides into the folloAV- 

 ing branches: — (a) An anterior branch, Avhich courses forwards in the muco- 

 periosteum at the junction of the hard palate Avith the alveolar process as far as the 

 anterior palatine foramen, Avhere it anastomoses Avith the naso-palatine artery; and 

 (l) ) posterior branches, Avhich pass backAvards and doAvnAvards into the soft palate, 

 contriljuting to the supply of that structure, and anastomosing Avith the ascending 

 palatine artery. After the operation for cleft palate, serious hnemorrhage occasion- 

 ally occurs from the descending palatine artery. It may be stopped by compressing 

 the artery by means of a plug inserted in the posterior palatine foramen. The 

 foramen is situated a little behind, and internal to, the last molar tooth, and almost 

 inmiediately in front of the hamular process. 



(4) The Vidian artery is a long slender branch Avhich passes backAvards 

 through the Vidian canal in company Avith the Vidian nerve into the cartilage of 

 tlie middle lacerated foramen. It gives off the folloAving branches: — (a) Pharyn- 

 geal, which contributes to the supply of the roof of the pharynx, and anastomoses 

 Avith the ascending pharyngeal and pterygo-palatine arteries; (/>) Eustachian, 

 Avhich is distributed to the Eustachian tube; and (c) tympanic, Avhicli enters tlu- 

 tyniipanum, and anastomoses Avith the other tympanic arteries. 



(5) The pterygo-palatine artery, or pterygo-pharyngeal as it is sometimes 

 called, a still more slender branch than the Vidian, passes backAvards througli the 

 pterygo-palatine foramen Avith the pharA'ngeal nerve, a branch of Meckel's ganglion. 

 It divides into three branches: — (o) Pharyngeal, to the roof of the pharynx; (6) 

 Eustachian, to the Eustachian tube; and (c) sphenoidal, to the sphenoidal cells. 

 The ]iterygo-palatine sometimes arises from the spheno-palatine. 



(6) The spheno-palatine or naso-palatine artery, the terminal branch of the 

 internal maxillary, ])asses Avith the spheuo-i)alatine l)ranch of Meckel's ganglion 

 from the spheno-maxillary fossa into the nose through the spheno-palatine foramen. 

 Crossing the roof of the nose in the nuico-periosteum, it passes on to the septum, 

 and then runs forwards and downwards in a groove on the vomer (under the name 

 of the naso-palatine, or artery of the septum) toAvards the anterior palatine 

 foramen, Avhere it anastomoses Avith the anterior palatine artery, Avhich enters the 

 nose through the lateral compartment of that foramen (the canal of !-^tenson). In 

 this course it gives off the folloAving branches: — (a) A pharyngeal branch (or 

 descending pharyngeal branch, as it is sometimes called), which is distributed 

 to the roof and contiguous ]iortions of the phar^'ux. (h) A sphenoidal branch, 

 which sup})lies the sjthenoidal cells, (r ) Nasal branches, Avliich ramify over the 

 turl)inal l»ones and lateral Avails of the nose, and give twigs to the ethmoidal and 

 frontal sinuses and lining membrane of the antrum. (//) Ascending septal 



