THE NERVOUS SYSTEM OF THE DOG 851 
buccal nerve, and ramifies on the lateral surface of the face. The inferior alveolar 
nerve arises by a common trunk with the mylo-hyoid; it gives off dental branches 
and terminates in mental and inferior labial branches. The lingual nerve supplies 
vaso-dilator and excito-secretory filaments to the mandibular and sublingual 
salivary glands; these fibers are derived from the chorda tympani. 
The facial nerve divides near the posterior border of the jaw into four branches. 
The upper branch is the auriculo-palpebral nerve, which divides after a very short 
course into anterior auricular and zygomatic branches. The latter curves upward 
and forward across the zygomatic arch toward the eye, and divides into branches 
which supply the eyelids and nasal region and concur with the frontal and lacrimal 
nerves in forming the anterior auricular plexus. The superior buccal nerve ac- 
companies the parotid duct across the masseter. The inferior buccal nerve runs 
forward along the lower border of the masseter and the mandible. The two nerves 
Fic. 682.—Dererp Dissection oF Heap or Doc, SHow1ne Espectatty TRIGEMINAL AND HyPpoGLossaL NERVES. 
a, Hypoglossal nerve; 6, cervical branch of a; c, mandibular division of trigeminus; d, lingual nerve; e, nerve to 
mandibular gland; f, deep temporal nerve; g, pterygoid nerve; h, buccinator nerve (cut); 7, inferior alveolar nerve; 
k, staphyline branch of lingual nerve; J, chorda tympani; m, mylo-hyoid nerve; n, sphenopalatine nerve; 0, lesser 
palatine nerve; p, great palatine nerve; q, infraorbital nerves; r,-n. subcutaneus male; s, branch of oculomotor nerve 
to inferior oblique muscle; ¢, lacrimal nerve; u, frontal nerve; », trochlear nerve; w, abducens nerve; 1, carotid artery; 
2, lingual artery; 3, internal maxillary artery; 4, m. thyro-pharyngeus; 5, m. hyo-pharyngeus; 6, m. thyro-hyoideus; 
7, m. sterno-hyoideus; 8, m. hyo-glossus; 9, m. genio-hyoideus; 10, m. genio-glossus; 11, m. stylo-glossus; 12, m. 
pterygoideus medialis; 13, outline of mandibular gland (dotted); 14, atlas; 15, bulla ossea; 16, zygomatic arch (dotted); 
17, m. rectus oculi inferior; 18, m. obliquus oculi inferior. (Ellenberger-Baum, Anat. d. Hundes.) 
ramify on the cheek and anastomose with each other and the infraorbital nerves 
to form a plexus from which branches go to the muscles of the lips and nostrils. 
The cervical branch runs downward and backward over the mandibular gland 
and ramifies in the cervical cutaneus muscle; it communicates with the inferior 
buceal nerve and sends twigs to the parotido-auricularis muscle and the mandibular 
space. 
The vagus bears a jugular ganglion and a ganglion nodosum. The former is 
situated on the nerve just before the emergence of the latter from the cranium. The 
latter is situated near the anterior cervical ganglion on the rectus capitis ventralis 
major and dorsal to the internal carotid artery; it is fusiform and may be about half 
an inch (ca. 1-1.5 em.) long ina large dog. In its course in the neck the nerve is 
inclosed with the sympathetic trunk in a common sheath and is related ventrally 
