THE PERIPHERAL NERVOUS SYSTEM. 



In a broad sense and as contrasted with the cerebro-spinal axis, the peripheral 

 nervous system includes all the nerve-paths by which the various parts of the body 

 are brought into relation with the brain and spinal cord. These paths embrace, in 

 a general way, two groups. One group, the somatic nerves, includes the nerves 



Fig. 1046. 



Olfactory bulO 



Orbital surface 

 of frontal lobe 



Temporal lobe 



Anterior 

 perforated space 



Maniniillary 

 bodies 



Cerebral 

 peduncle 



Pons 



Medulla. ; 

 pyramid \;i 



Hypoglossal 

 nerve 



Cerebellum 



Anterior roots of spinal nerves 



Olfactory tract 



Optic nerve, cut 



Optic 

 commissure 



Optic tract 



Oculomotor 

 nerve 



Trochlear nerve 

 Trigeminal 

 nerve 



Abducent nerve 



Facial nerve 



Auditory nerve 

 Glosso-pharyn- 

 geal ner\'e 

 Pneumogastric 

 nerve 

 Spinal 



accessory nerve 

 spinal portion 



Pyramidal 

 decussation 



Spinal part of 

 XI. nerve 



Occipital lobe 



Inferior aspect of brain, aenuded of its membranes, showing superficial origins of cranial nerves ; origin 01 trochlear 



nerve is on dorsal surface and therefore not seen. 



supplying the voluntary muscles, integument and organs of special sense ; the sec- 

 ond group, the visceral nerves, includes those supplying the involuntary muscle 

 throughout the body and the thoracic and abdominal viscera. The somatic nerves 

 are subdivided into (a) the cranial nerves, which are attached to the brain and pass 

 through foramina in the skull, and {b) the spinal nerves, which are attached to the 

 spinal cord and traverse the intervertebral foramina. The visceral, or splanchnic 

 121S 



