THE NERVOUS SYSTEM OF THE PIG 



845 



The lacrimal nerve resembles that of the horse, the frontal that of the ox. 

 The naso-ciliary nerve is relatively large and sends numerous filaments to the ocular 

 muscles. The maxillary nerve has a very short course in the pterygo-palatine 

 fossa. The infraorbital nerve is large in correlation with the development of the 

 snout, which receives numerous branches. The mandibular nerve emerges through 

 the foramen lacerum anterius. The superficial temporal nerve is small; according 

 to Moussu it furnishes the excito-secretory fibers to the upper part of the parotid 

 gland, while those going to the lower part are derived from the mylo-hyoid nerve. 



The inferior buccal nerve passes downward and forward under cover of the 

 parotid gland and accompanies the parotid duct, with which it turns around the 

 lower border of the jaw in front of the masseter. 



The vagus bears a jugular ganglion and a ganglion nodosum ; the latter occurs 



Ulnar nerve 

 {dorsal branch) 



Anastomotic _ 

 branch 



Radial 



nerve 



(cutaneous 



branch) 



7 Ulnar nerve 

 "Dorsal branch 



^-Deep branch 



Fig. 673. — Nerves of Distal Part of Right Foee- 



LiMB of Pig; Dorsal View (Schematic). 



c, Dorsal common digital nerves; p, dorsal proper 



digital nerves. 



Fig. 



674. — Nerves of Distal Part of Right Fore- 

 limb OF Pig; Volar View (Schematic). 

 p. Volar proper digital nerves. 



at the point of origin of the anterior laryngeal nerve, and may be as large as a small 

 pea. Proximal to this the vagus is easily divided into two strands, one of which is 

 the accessory component. The cesophageal trunks form a posterior oesophageal 

 plexus, as in man, from which two nerves issue. The ventral nerve is small and 

 ramifies on the parietal surface of the stomach. The dorsal nerve is much larger; 

 it gives branches to the stomach, crosses the lesser curvature of that organ, and 

 joins the coeliac plexus. 



The hjrpoglossal nerve may present a small dorsal root, on which there is a 

 minute hypoglossal ganglion. 



The spinal nerves number on each side eight in the cervical region, fourteen 

 (commonly) in the thoracic, seven in the lumbar, and four in the sacral. Some 

 ■of the special features of the nerves of the limbs are as follows: 



