548 



BLOOD-VASCULAR SYSTEM OF THE HORSE 



of the facial nerve and deeply by the parotid duct. The artery terminates over 

 the levtaor labii superioris proprius l)y dividing into the dorsal nasal and the angu- 

 lar artery of the eye. The chief l)ranches of the external maxillary are as follows: 



(1) The pharyngeal artery (A. palatina ascendens) arises usually behind the 

 stylo-pharj-ngeus, jmsses between that muscle and the great cornu, and runs for- 

 ward on the lateral wall of the pharynx under the elastic pharyngeal fascia. It is 

 distributed to the soft jialate, pharynx, and tonsil. 



(2) The lingual artery (A. lingualis) is a large branch which diverges from the 

 parent trunk' at an acute angle, runs along the ventral border of the great cornu 

 of the hyoid bone, and dips under the hyo-glossus muscle. It then passes across 



Fig. 4.3.5. — Superficial Dissection of Head of Horse. Most of the Panniculus is Removed. 

 a, Dilatator naris superior; b, levator labii superioris proprius; c, levator naso-labialis; d, dilatator naris 

 lateralis; e, buccinator; /, zygomaticus; (/, depressor labii inferioris; h, stump of retractor anguli oris; ;', mas- 

 .seter; A;, k, scutularis; /, scutulo-auriculares sui)erfioiaIes; m, zygoniatico-auricularis; n, parotido-auricularis; o, 

 stylo-maxillaris; p, steriio-cei)halicus; /)', tendon of /)," q, omo-hyoideus; r, splenius; s, tendon of sj)leni<is and 

 f rachelo-ina.stoidevis; t, corrugator superrilii; », orbicularis oris; v, parotid gland; u', zygomatic arch; jr, scutiform 

 cartilage; y, upper commissure of nostril; /, facial nerve; S, superior buccal nerve; S, inferior buccal nerve; 4, 

 transverse facial nerve; 5, cervical branch of facial nerve; 6, posterior auricular branch of second cervical nerve; 

 7, cutaneous cervical branch of same; A", infratrochlear nerve; 9, frontal nerve; JO, lacrimal nerve; 10', end of 

 auriculo-palpebral nerve; 11, inferior masseteric artery and vein; 12, transverse facial artery and vein; IS, facial 

 artery; 14, inferior labial artery; 16, superior labial artery; 16, lateral nasal artery; 17, dorsal nasal artery; IS, 

 angular artery of the eye; /9, posterior auricular artery; ^0, 2/, jugular vein; ;?^, external maxillary vein; 33, 

 great auricular vein; 34, jiarotid duct; 34', origin of same, (.\fter Ellenberger-Baum, Top. .\nat. d. Pferdes.) 



the kerato-hyoideus, turns inward under the intercornual joint of the hyoid ])one, 

 and runs forward in the tongue between the hyo-glossus and genio-glossus. This 

 l)art (A. i)r()funda linguie) is flexuous and is accompanied by branches of the hypo- 

 glossal and lingual nerves. It is th(> chief artery of the tongue, and anastomoses 

 with the opposite^ artery and the sublingual. 



(3) The sublingual artery (A. sublingualis) is a smaller vessel which arises at 

 the anterior extremity of the submaxillary gland (Fig. 43G). It passes forward on the 

 anterior bell}' of the digastricus betwecui the ranuis of the mandible and the mylo- 

 hyoideus, perforates the latter, runs along the lower border of the sublingual gland, 

 and ramifies in the mucous membrane of the anterior part of the floor of the mouth. 



