THE EXTERNAL CAROTID ARTERY - 643 
A considerable branch may be given off in the mandibular space, which turns around 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 external 
maxillary a little before it reaches the depressor labii inferioris (Fig. 560). 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 membrane of the cheek, and the lower lip, anastomosing with 
the mental artery and the corresponding vessels of the opposite side. It detaches 
Fic. 560.—Surerrictat Dissection oF Heap oF Horse. Most or THE CuraNeUs Is REMOVED. 
a, Lateralis nasi; b, levator labii superioris proprius; c, levator naso-labialis; d, dilatator naris lateralis; e, bue- 
cinator; f, zygomaticus, posterior part of which is removed; g, depressor labii inferioris; k, stump of retractor anguli 
oris; i, masseter; k, k, scutularis; /, scutulo-auriculares superficiales; m, zygomatico-auricularis; n, parotido-auricu- 
laris; 0, occipito-mandibularis; p, sterno-cephalicus; p’, tendon of p; g, omo-hyoideus; 1, splenius; s, tendon of sple- 
nius and longissimus capitis; ¢, corrugator supercilii; u, orbicularis oris; 2, parotid gland; w, zygomatic arch; z, scuti- 
form cartilage; y, upper commissure of nostril; 1, facial nerve: 2, superior buccal nerve; 3, 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; 8, infratrochlear nerve; 9, frontal nerve; 10, lacrimal nerve; 10’, end of auriculo- 
palpebral nerve; 11, masseteric artery and vein; 12, transverse facial artery and vein; 13, facial artery; 14, inferior 
labial artery; 15, superior labial artery; 16, lateral nasal artery; 17, dorsal nasal artery; 18, angular artery of the eye; 
19, posterior auricular artery; 20, 21, jugular vein; 22, external maxillary vein; 23, great auricular vein; 24, parotid 
duct; 24’, origin of same; 25, superior buccal glands; 26, facial vein. (After Ellenberger-Baum, Top. Anat. d. Pferdes.) 
a branch (A. anguli oris) to the angle of the mouth, which anastomoses with the 
superior labial. 
(5) The superior labial artery (A. labialis superior) arises from the facial in 
front of the facial crest (Fig. 560). It passes forward under the dilatator naris lat- 
eralis and levator nasolabialis to the upper lip, gives twigs to the upper part of the 
cheek and the lateral nasal region, and ramifies in the upper lip, anastomosing with 
the opposite artery and the palato-labial. 
(6) The lateral nasal artery (A. lateralis nasi) arises usually a little above the 
preceding one, and runs forward parallel with it and under the levator nasolabialis 
to the nostril (Fig. 560). It supplies branches to the lateral nasal region and the 
nostril. 
