234 



HUMAN PHYSIOLOGY 



CHAP. 



each other ; they are called commissural fibers. Third, 

 those that connect the lobes and convolutions in each 



FIG. 129. Projection fibers 

 (Zuppke) . 



FIG. 130. Commissural fibers 

 (Zuppke). 



hemisphere ; they are known as association fibers. By 

 means of the different kinds of nerve fibers every part 



of the body, fingers and 

 toes, elbows and knees, 

 shoulders and hips, eyes 

 and ears, is connected with 

 the cerebrum and may 

 send information to it, and 



FIG. 131. Association fibers 

 (Zuppke). 



receive responses and mes- 

 sages from it. 



161. The Sympathetic Nervous System. We have 

 learned that there are twelve pairs of cranial nerves 

 which branch off from the brain, and pass out of the 

 skull through openings in the bones and distribute 

 themselves to many organs of the head, chest, and 

 abdomen ; and thirty-one pairs of spinal nerves which 

 connect the cord with the skin, and with all the skeletal 

 muscles except some about the head and face. Besides 



