644 



BLOOD-VASCULAR SYSTEM OF THE HORSE 



The vessel is often double. It may arise from the superior labial at the point of bifurcation 

 of the facial or with the dorsal nasal from the infraorbital artery (as in the ox). In some cases 

 it gives off a dorsal nasal branch. 



(7) The dorsal nasal artery (A. dorsalis nasi) arises on the levator labii superi- 

 oris proprius and passes forward under the levator nasolabialis to the dorsum nasi 

 (Fig. 560). 



(8) The angular artery of the eye (A. angularis oculi) runs toward the medial 



Fig. 561. — Paeotid, Masseteric, and Lixgual Regions of Horse; Deep Dissection, Third Layer. 

 a, Mylo-hyoideus, anterior part, reflected; b, genio-hyoideus; c, genio-glossus; d, sublingual gland; e, ramus of man- 

 dible, greater part removed; e', stump of masseter; /, maxillary tuberosity; g, great cornu of hyoid bone; h, wing of atlas; 

 i, intermediate tendon of digastricus; i'y anterior belly, i", posterior belly, of digastricus; k, posterior part of mylo- 

 hyoideus; I, hyo-glossus; m, pterygoideus medialis (cut); 7i, stylo~hy oideus ; o, occipito-mandibularis; p, crico- 

 pharyngeus; g, obliquus capitis ant. ; r, tendon of longissimus atlantis; s, rectus cap. ventralis; t, brachiocepiialicus 

 (cut) ; u, sterno-cephalicus (cut); v, sterno-thyroideus (cut) ; it?, sterno-hyoideus (cut); x, omo-hyoideus; y, obliquus 

 cap. post.; 2, splenius (cut) ; i-4, upper cheek teeth; .{', last cheek tooth; 5, stump of facial nerve ; 5, stump of bucci- 

 nator nerve; 7, lingual nerve; 7', superficial branch, 7", deep branch, of lingual nerve; S, stumps of inferior alveolar 

 artery, vein and nerve; 9, mylo-hyoid nerve (cut) ; 10, glosso-pharyngeal nerve; ??, hypoglossal nerve ; 12, anterior laryn- 

 geal nerve; 13, ventral branch of first cervical nerve; 14, vagus and sympathetic; 15, dorsal branch of spinal accessory 

 nerve; i 6', ventral branch of same; i 7, ventral cerebral vein; i5, mandibular duct; J P, common carotid artery; SO, 

 parotid branch; 21, thyro-laryngeal artery; 22, pharyngeal arterj^; 23, laryngeal artery; 24, interna! carotid artery; 

 2J, occipital artery; 26, external carotid artery-; 27, 31, external maxillarj^ artery; 28, pharyngeal artery; 29, lingual 

 artery; 30, sublingual artery; 32, external carotid artery after emergence; 33, internal maxillary vein (origin); 34, 

 remnant of parotid gland; 33, thyroid gland; 36, jugular vein; 37, parapharyngeal lymph glands, (-\fter Ellen- 

 berger-Baum, Top. Anat. d. Pferdes.) 



canthus of the eye, where it anastomoses with the orbital branch (Ramus malaris) 

 of the infraorbital artery (Fig. 560) . 



In addition to the preceding, unnamed branches are supplied to the mandibu- 

 lar salivary gland and lymph glands. There is commonly a branch of considerable 

 size which is given off as the external maxillary artery passes the anterior end of the 

 mandibular gland; it runs upward and backward along the dorsal border of the 

 gland, which it supplies. 



3. The posterior auricular artery (A. auricularis posterior) arises at an acute 

 angle from the external carotid just above the origin of the masseteric. It passes 



