ANATOMY, PHYSIOLOGY, OF NERVOUS SYSTEM. 427 



arise in a number of scattered places in the medulla, and in 

 this way are brought into direct communication with quite 

 a number of different centers and fibers. After the passage' 

 of the sensory branch through the Gasserian ganglion it 

 unites with the motor branch to form the main trunk. This 

 trunk, however, soon divides into three main branches, 

 hence the name of the nerve, which in a general way are 

 distributed as follows: a. The ophthalmic branch going to 

 the muscles and skin of the forehead and upper eyelid, and 

 the mucous membrane of the nose. b. The superior max- 

 illary branch innervating the skin of the temples, the cheeks 

 and the angle of the mouth and upper teeth, and within the 

 mouth the mucous membrane or pharynx and soft palate. 

 c. The inferior maxillary, distributed to the side of the 

 head, the external ear, the skin of the lower part of the 

 face, the lower teeth, the salivary glands, the top of the 

 tongue and the muscles which move the lower jaw in the 

 process of mastication. 



While anatomically it is thus divided into three branches 

 physiologically it contains quite a number of different kinds 

 of nerves as follows: (1) Sensory nerves. It is the sen- 

 sory nerve for the dura mater, for the skin of the entire 

 face, for the orbit of the eye as well as the ball of the eye, 

 for the nose, the mouth, the top of the tongue, the gums, 

 the teeth, the surface of the ear and the auditory meati. In 

 a word, by means of this nerve the sensation of touch is 

 made possible in all the regions mentioned. (2) Motor 

 fibers. It innervates the muscles of mastication, a muscle 

 of the soft palate and the tensor muscle of the midde ear. 

 (3) Secretory fibers to the lachrymal glands, arousing 

 these to the secretion of the tears. (4) Gustatory nerves 

 which are distributed to the tongue. This function is de- 

 nied by some observers, but it is probable that the sensations 

 of sweet and sour at the tip of the tongue are carried by this 

 nerve. (5) Vaso-motor fibers for the blood-vessels of the 

 eye, the gums and the tongue, by means of which the vas- 

 cular supply of these structures is to a certain extent con- 



