THE EXTERNAL CAROTID ARTERY 



549 



It detaches branches to the muscles and skin in the submaxillary space, the sub- 

 maxillary lymph glands, and the sublingual gland. It also gives off the small 

 submental artery, which runs forward superficially toward the lower lip, supplying 

 twigs to the skin and the mylo-hyoideus. 



Fig. 436. — Parotid, Masseteric, and Lingual Regions of Horse: Deep Dissection, Third Layer. 

 a, Mylo-hyoideus, anterior part, reflected; b. geiiio-hyoideus; c, genio-glossus; d, sublingual gland; r, 

 ramus of mandible, the greater part of which is removed; e' , stump of masseter; /, maxillary tuberosity; (i, great 

 cornu of hyoid bone; h, wing of atlas; t, intermediate tendon of digastricus; i' , anterior belly, i", posterior belly 

 of digastricus; k, posterior part of mylo-hyoideus; /, hyo-glossus; m, pterygoideus internus (cut) ; n, stylo-hyoiiieus; 

 o, stylo-niaxillaris (cut); p, crico-pharyngeus; g, obliquus capitis ant.; r, tendon of trachelo-mastoideus; 

 s, rectus cap. ant. major; t, mastoido-humeralis (cut); u, sterno-cephalicus (cut); i\ sterno-thyroideus 

 (cut) ; u', sterno-hyoideus (cut) ; x, omo-hyoideus; y, obliquus cap. post.; z, splenius (cut) ; 1-4, upper cheek teeth; 4', 

 last cheek tooth; 6, stump of facial nerve; 8, stump of buccinator nerve; 7, lingual nerve; 7', superficial branch, 7", 

 deep branch of lingual nerve; 8, stumps of inferior alveolar artery, vein and nerve; 9, mylo-hyoid nerve (cut); 10, 

 glosso-pharyngeal nerve; 11, hypoglossal nerve; 12, superior laryngeal nerve; i5, ventral branch of first cervical 

 nerve; 74. vagus and sympathetic; /5, dorsal branch of .spinal accessory nerve; 76, ventral branch of same; 17, 

 inferior cerebral vein; 7<S, submaxillary duct; 75, common carotid artery; .20, parotid branch; 21, thyro-laryngeal 

 artery; 5.3, pharyngeal artery; .?■?, laryngeal artery; .24, internal carotid artery; .2.5, occipital artery; .2ff, external 

 carotid artery; 27-31, external maxillary artery; 28, jsosterior palatine artery; 29, lingual artery; 30, sub- 

 lingual artery; 32, internal maxillary artery; 33, internal maxillary vein (origin); 34, remnant of parotid gland; 

 35, thyroid gland; 36, jugular vein; 37, pharyngeal lymph glands. (After Ellenberger-Bauin, Toj). Anat. d. 

 Pferdes.) 



In 3ome cases the sublingual artery ari.ses from the lingual and tlie submental from the 

 external maxillary. Sometimes the sublingual remains on the external face of the mylo-hyoideus 

 — thus resembling the submental of man — and the sublingual gland is supi^lied by a special 

 branch of the lingual. 



Not uncommonly a considerable branch, given ofT in the sul)maxillary space, tiuTis round 

 the lower border of the jaw and enters the middle of the lower part of the masseter muscle. In 

 some cases this artery is of large size and its pulsation can be felt. It is accompanied by a vein. 



(4) The inferior labial artery (A. labialis inferior) arises from the facial a little 

 before it reaches the depressor labii inferioris (Fig. 435). It passes forward, dips 

 under the depressor muscle, and continues to the lower lip. It supplies branches to 

 the muscles and skin in this region, to the inferior buccal glands, the mucous mem- 

 brane of the check, and the lower lip, anastomosing with the mental artery and the 

 corresponding vessels of the opposite side. It detaches a branch (A. anguli oris) 

 to the angle of the mouth, which anastomoses with the superior labial. 



