226 THE NERVOUS SYSTEM 



Fourth Pair. The Patheticus 



Its only function is to control the action of the superior 

 oblique muscle of the eye. 



Fifth Pair. TJie Trigeminus 



This is the great sensitive nerve of the face, supplying the 

 skin and mucous membrane of this region. It also has motor 

 fibres which control certain muscles of the face. It also sup- 

 plies certain parts of the eye, nose, and lachrymal glands, the 

 teeth in both the upper and lower jaws, the salivary glands, 

 and the tongue. 



Sixth Pair. The Abducens 



It is exclusively a motor nerve, controlling only one muscle, 

 namely, the external straight muscle of the eyeball. 



Seventh Pair. Tlie Facial Nerves 



They are the motor nerves for the superficial muscles of the 

 face, and may be correctly called the nerves of expression, by 

 which the features are animated in their varying movements, 

 corresponding with the different phases of mental or emotional 

 activity. 



Eighth Pair. TJie Auditory Nerves 



They are distributed to the internal ear only, and form the 

 only connection between this and the brain, transmitting the 

 nerve .impulses which produce the sensation of sound. 



Ninth Pair. TJie Glossopharyngeal Nerves 



They are both sensitive and motor nerves, controlling the 

 sense of taste and the act of deglutition. 



14. What is stated of the olfactory nerves ? The optic nerves ? 

 The oculomotorius ? The patheticus ? The trigeminus ? 

 The abducens ? The facial nerves ? The auditory nerves ? 

 The gloasopharyngeal ? 



