CRANIAL NERVES. 125 



Anatomical Classification of the Cranial Nerve*. 



First Pair. Olfactory ; special nerve of smell. 



Second Pair. Optic ; special nerve of sight. 



Third Pair. Motor oculi communis ; motor nerve die 

 tributed to all of the muscles of the eyeball, except the ex- 

 ternal rectus and the superior^ oblique, to the iris, and the 

 levator palpebrae. 



Fourth Pair. Patheticus, or trochlearis ; a motor 'nerve 

 sent to the superior oblique muscle of the eye. 



Fifth Pair. A small motor root (nerve of mastication) 

 distributed to the muscles of mastication, and a large root 

 (the trifacial), the nerve of general sensibility of the face. 



Sixth Pair. Motor oculi externus, or abducens ; a mo- 

 tor nerve passing to the external rectus muscle of the eye. 



Seventh Pair. Portio mollis, or auditory, a special nerve 

 of hearing ; and the portio dura, or facial ; a motor nerve 

 distributed to the superficial muscles of the face. 



Eighth Pair. Glosso-pharyngeal ; pneumogastric, or par 

 vagum ; spinal accessory. Three mixed nerves, with quite 

 extensive distributions. 



Ninth Pair. Sublingual, or hypoglossal ; a motor nerve 

 distributed to the tongue. 1 



Physiological Classification. 



(a.) Nertes of Special Sense. 

 Olfactory. 



Optic. 



Auditory. 



Gustatory, comprising a part of the glosso-pharyngeal 

 and a small filament from the facial to the lingual branch of 

 the fifth. 



1 According to the classification of Sommering, the arrangement is the same 

 for the first, second, third, fourth, fifth, and sixth. The facial is called the sev- 

 enth ; the auditory, the eighth ; the glosso-pharyngeal, the ninth ; the pneumo- 

 gastric, the tenth; the spinal accessory, the eleventh; and the sublingual, the 

 twelfth. 



