82 LABORATORY EXERCISES. 



B. Hair. 



1 . On what portions of the hand is hair found ? 



Where is it wanting? 



2. Compare the hair on the surface of your 



hand with that on the hand of an 

 older person. What difference do you 

 note? 



3. Do blood-vessels run into the hair? How 



do you know? 



4. Which part of the hair is supplied with 



nerves? How do you know? 



C. Nails. 



1. What different areas do you notice in your 



thumb-nail? How do they differ in ap- 

 pearance? 



2. Make a drawing of your thumb-nail, show- 



ing these different regions. 



3. Scrape off a little of the outer surface of the 



nail; does this cause blood to flow? Are 

 nails supplied with blood-vessels? 



D. Deeper layers of the skin. 



1. With the thumb and forefinger of the right 



hand grasp a portion of the skin on the 

 back of the left hand. Can you lift the 

 skin from the muscles and tendons lying 

 below ? 



2. In the same way determine whether the 



skin on the palm of the hand and on the 

 ringers is closely or loosely attached to 

 the underlying tissue. What do you 

 find to be true? 



3. Determine the effect of pushing a clean 



