THE NERVObiS iSVSTJOM 405 



fibers which run around into the lower hind])rain or medull-i This 

 band of fibers is called the pons. The medulla is, in structure 

 part of the spinal cord, and is made up lar^rdy of fibers runninJ 

 longitudmally. Just above the pons, these fil.ers are collected into 

 two bundles which separate and pass up, one to each hemisphere 

 of the cerebrum. The bundles are called the crura cerebri 



Sensory and Motor Nerve Fibers. — Nerves which are connected 

 with the central nervous system may be made up of fibers bearine; 



Face 



Sensory 



Face — 

 Motor 



Tovigue 



nd 



Spinal Nerves 



Heart \ 



Lungs \ 



Stomach 1 



Liver J 





Diagram of the distribution of the cranial nerves. 



sensations from the skin or sense organs to the central nen-ous 

 system, the sensory fibers, or of other fibers which carry impulses 

 from the central nervous system to the outside, the motor fibers. 

 Some nerves are made up of both kinds of fibers, in which ciise they 

 are called mixed nerves. 



Distribution of Cranial (Brain) Nerves in Frog and Man. — In 

 the frog, the cranial nerves agree in function with the tirst ten 

 nerves, or cranial nerves, of man. There are t\f o additional cranial 

 nerves, however, found in man. These nerves are distributed a.*? 

 shown in the table on the following page. 



