40 ELEMENTARY PHYSIOLOGY. 



To serve the mind in directing the voluntary 



movements of the body. 

 To control, by reflex action, the involuntary mus- 



WHY? { cles * 



To bring to the mind, from the body and from the 



outside world, impressions producing the sensa- 

 tions or feeling of touch, taste, light, sound, 

 smell, pain or pleasure. 



QUESTIONS. 



What are the organs of the nervous system? 



What position in the body does the brain occupy? 



Whose special instrument does the brain seem to be? 



What can you say of the brain's structure? 



What difference in the color of its substance? 



Describe how the brain is protected. 



What is the cerebrum? 



What is the cerebellum? 



What is the arbor vitse? 



What is meant by the hemispheres of the brain? 



What can you tell of the work of the cerebrum? 



What seems to be the use of the cerebellum? 



Where is the spinal cord ? 



What is its upper part called? 



What makes this part so very important? 



What are the nerves? 



From where do they start? 



Where do they go? 



How many pairs pass out from the skull? 



What are these nerves called? 



How many pairs branch off from the spinal cord? 



What are these called? 



Where do the cranial nerves chiefly go? 



To what part are the spinal nerves chiefly sent? 



What can you tell of the sympathetic nerves? 



To what have we compared the nervous system? 



Tell what you can of the comparison. 



Do all the nerves perform the same kind of work? 



Explain what is meant by the nerves of motion. 



