THE INTERNAL MAXILLARY ARTERY 



551 



It turns around the neck below the condyle of the mandible and emerges from be- 

 neath the parotid gland (Fig. 435). It then passes forward a short distance on 

 the masseter about half an inch below the zygomatic arch and plunges into the 

 muscle, in which it commonly divides into two chief branches. It is accom- 

 panied by a vein and a branch of the superficial temporal nerve. It supplies the 



Fig. 437. — Deep Dissectiox of Head of Horse. 



The left ramus of the mandible and structures connected with it have been removed, a, a. Stumps of 

 styloglossus; b, genio-glossus; c, genio-hyoideus; d, omo-hyoideus; e, kerato-hyoideus; /, thyro-hyoideus; g, thyro- 

 pharyngeus; h, crico-thyroideas; (', sterno-thyroideus; k, thyroid gland; m, crico-pharyngeus; n, palatinus and 

 palato-pharyngeus; o, pterygoideus externus; p, tensor palati; q, levator palati; r, temporalis; s, rectus cap. ant. 

 major; (, obliquus cap. ant.; ii, guttural pouch; r, great cornu of hyoid bone, posterior extremity of which is 

 removed and in<iicated by dotted line; w, position of small cornu, dotted line; t, thyroid cornu; y, tongue; z, 

 anterior pillar of soft palate; 1 , superficial temporal ner\-e; 3, chorda tympani; S, stump of inferior alveolar nerve; 

 4- 4, lingual nerve, intermediate part removed; 5, deep temporal nerve; 6, masseteric nerve; 7, buccinator nerve; 

 S, great palatine nerve; 9, infraorbital nerve; 10, sphenopalatine and posterior nasal nerves; 11, spinal accessory 

 nerve; 12, vagus; 13, pharyngeal branch of vagus; 14, superior laryngeal nerve; 16, vago-sympathetic trunk; 

 16, sympathetic, with superior cervical ganglion a little further back; 17, glosso-pharyngeal nerve; IS, pharyngeal 

 and 79, lingual branches of glosso-pharyngeal; ^0, hypoglossal nerve; £1 , left recurrent nerve; .2.3, common carotid 

 arterj'; 23, parotid branch; 24, thyro-laryngeal artery; 24', laryngeal artery; 23, occipital artery; 26, internal 

 carotid artery; 27, external carotid artery; 2S-30, external maxillary artery; 29, pharyngeal artery; 31, lingual 

 artery; 32, internal maxillary arterj-; 33, stump of inferior alveolar artery; 34, middle meningeal artery; 35, 

 deep temporal artery; 36, buccinator artery; 37, palatine artery; 38, end of internal maxillary artery; 39, 

 right external maxillary artery; 40, satellite vein of 39; 41, right jjarotid duct; 4^, submaxillary lymph glands; 

 43, pharyngeal lymph glands; 4.^, trachea; 4-5, wing of atlas; .^5, dotted line indicating outline of submaxillary 

 gland; 47, lacrimal gland. (After Ellenberger-Baum, Top. Anat. d. Pferdes.) 



masseter and the skin of this region, and anastomoses with the external maxil- 

 lary and posterior deep temporal arteries. 



The pulse may iLsually be felt in this artery as it passes below the articulation of the jaw. 



THE INTERNAL MAXILLARY ARTERY (Figs. 437. 438, 439) 



This artery (A. maxillaris interna) is much the larger of the two terminal 

 branches of the external carotid. It begins at the inner side of the posterior border 



