BEANCHES OF THE EXTEENAL CAEOTID AETEEY. 893 



the tongue as far back as the epiglottis, and sends branches, posteriorly, to the palatine 

 tonsil which anastomose with the tonsillar twigs of the ascending palatine branch of the 

 external maxillary and with the ascending pharyngeal artery. 



(c) A sublingual branch arises at the lower part of the anterior border of the hyo- 

 glossus muscle and runs anteriorly and upwards, between the mylo-hyoid and the genio- 

 glossus, to the sublingual gland, which it supplies; it also supplies the mylo-hyoid, the 

 genio-glossus, and the genio-hyoid muscles. It anastomoses with its fellow of the opposite 

 side, with the arteria profunda by a branch which it sends along the frenulum linguae, and, 

 through the mylo-hyoid muscle, with the submental branch of the external maxillary. 



(3) Arteria Maxillaris Bxterna (O.T. Facial). The external maxillary artery 

 (Fig. 759) arises from the front of the external carotid, immediately above the 

 lingual. It ends at the angle of the mouth, where it becomes the angular artery. 



Course. It commences in the carotid triangle, immediately above the lingual, 

 and passes upwards to the angle of the mandible, on the lateral surface of the 

 middle constrictor muscle. Still ascending, it lies between the posterior belly 

 of the digastric and the stylo-hyoid muscles laterally, and the superior constrictor 

 medially, and it is separated from the palatine tonsil by the superior constrictor. 

 When it reaches the upper border of the stylo-hyoid it enters a groove in the 

 posterior part of the subinaxillary gland and runs downwards and anteriorly, 

 between the lateral surface of the gland and the internal pterygoid muscle, to the 

 posterior end of the lower border of the body of the mandible. There it pierces 

 the deep cervical fascia, turns round the inferior border of the mandible, at the 

 : anterior border of the masseter, enters the face and continues upwards and forwards 

 to its termination. 



Relations. In the carotid triangle the artery is comparatively superficial, except 

 just at its origin, which is overlapped by the anterior fibres of the stern o-mastoid muscle. 

 As it ascends it is in relation, on the medial side, with the middle and superior constrictor 

 muscles, and, as already stated, the superior constrictor separates it from the palatine 

 tonsil. Its relations between the point where it passes medial to the posterior belly of the 

 digastric and the point where it turns round the lower border of the mandible have been 

 ! given in the description of its course. 



After turning round the lower border of the body of the mandible, which it grooves 

 slightly, the artery becomes more superficial than in any other part of its course, being 

 covered only by platysma, fascia, and skin. At that point the anterior facial vein is 

 immediately posterior to the artery, lying on the surface of the masseter. In the face 

 the artery lies between the platysma, the risorius, the zygomaticus major, and the infra- 

 orbital section of the quadratus labii superioris (O.T. leva tor labii superioris), which, with 

 skin and fascia, are superficial to it, and the buccinator and the musculus caninus (O.T. 

 levator anguli oris), which are deeper. The termination of the artery is in the substance 

 of the quadratus labii superioris. 



The anterior facial vein, though still posterior to the artery in the face, runs a some- 

 what straighter course, and is situated at some little distance from it. 



Branches. Four named branches are given off in the neck, and several in the face. 



In the Neck. (a) The ascending palatine branch (Fig. 761) is a small artery which 

 arises from the external maxillary under cover of the posterior belly of the digastric. It 

 ascends, and, after passing between the stylo-glossus and the stylo-pharyngeus muscles, 

 reaches the apex of the petrous portion of the temporal bone, where it turns downwards, 

 accompanying the levator veli palatini muscle, pierces the pharyngeal aponeurosis, and 

 enters the soft palate. 



It supplies the lateral wall of the upper part of the pharynx, the soft palate, the 

 palatine tonsil, and the auditory (O.T. Eustachian) tube, and it anastomoses with the 

 tonsillar branch of the external maxillary, the dorsalis linguae, the descending palatine 

 branch of the internal maxillary, and with the ascending pharyngeal artery, which 

 sometimes replaces it. 



(b) The tonsillar branch, a small artery which arises close to the ascending palatine. It 

 passes upwards between the internal pterygoid and the stylo-glossus, pierces the superior 

 constrictor, and terminates in the palatine tonsil. It supplies the middle and superior 

 constrictor muscles, and it anastomoses with the dorsalis linguae, with the ascending 

 palatine branch, and with the ascending pharyngeal artery. 



(c) The submaxillary or glandular branch is frequently represented by two or three 

 small twigs which pass directly into the submaxillary gland. 







