HEAD AND NECK OF THE HORSE 37 



The dorsal buccal nerve (n. buccalis dorsal is) crosses the masseter 

 muscle parallel to the facial crest, and thus gains the cheek, where, in 

 many cases, it divides into two branches. The dorsal branch is 

 connected with filaments from the infra-orbital nerve, and ends in the 

 muscles of the upper lip and nostril. The lower or ventral branch is 

 connected with the ventral buccal nerve and terminates in the muscles 

 of the cheek and upper lip. When, as often happens, no definite 

 division takes place, the dorsal buccal nerve can be followed forwards 

 underneath the zygomatic, naso-labial and canine muscles, in company 

 with the superior labial artery, to the nostril and upper lip. 



The ventral buccal nerve (n. buccalis ventralis) crosses the masseter 

 muscle obliquely, following a course that is nearly parallel to that of the 

 dorsal nerve, with which it is generally connected by variable 

 anastomoses. On the depressor muscle of the lower lip one of its 

 branches joins twigs from the buccinator nerve. The terminal filaments 

 of the ventral buccal nerve supply the muscles of the lower lip and the 

 cheek, 



N. TEMPORALIS SUPERFICIALIS. — The Superficial temporal nerve 

 is a comparatively small branch of the mandibular (part of the 

 fifth cerebral nerve) and turns round the border of the ramus of the 

 mandible in company with the transverse facial vessels. At this point 

 the transverse facial artery separates it from the common trunk of the 

 two buccal nerves. 



The superficial temporal nerve, at a variable point, divides into 

 two branches. The smaller and more dorsal branch (ramus transversus 

 faciei) follows the transverse facial vessels to end in the skin of the 

 cheek. The larger, ventral branch crosses the dorsal buccal nerve 

 obliquely near its origin, and joins the ventral buccal which it accom- 

 panies over the masseter muscle. Its filaments supply the masseter 

 and cutaneous muscles and the skin over them. 



A. FACIALIS. — The facial artery is the continuation of the external 

 maxillary from the border of the mandible. The external maxillary 

 vessels and the parotid duct have been followed in the space between 

 the two halves of the mandible ; and it has been observed that, of the 

 three structures, the duct is most ventral and the artery most dorsal. 

 Their facial continuations maintain the same relative positions; con- 

 sequently the parotid duct is most posterior, the facial artery is most 

 anterior, and the facial vein lies between the duct and the artery. 



The facial artery follows the anterior border of the masseter muscle 

 until this terminates at the end of the facial crest. Thereafter the 

 artery curves upwards and backwards to end close to the margin of 



