THE SKIN 



Skin from the Palm 

 of the Hand, natural 

 size. 



i, epidermis ; 2, papillae ; 

 3, dermis ; 4, subcutane- 

 ous tissue and sweat 

 glands. 



To get the number in one square inch, multiply by itself 



the number in a row one inch long. There are about 



2,400,000 sweat glands in the entire body. They are most 



numerous in the palm. If a sweat 



gland averages one fourth inch in length, 



how many miles would they extend if FIG. 5. section of the 



placed end to end ? 



8. THOUGHT LESSON. Anatomy and 

 Physiology of the Skin. i . What 

 fraction of an inch in thickness do you 

 judge the skin on the back of the hand 

 to be ? (A fold shows double thickness.) 



2. Feel and observe the skin, and write five qualities 

 possessed by it. 



3. What evidence have you ever had that the skin has 

 two layers ? 



4. How long will a pair of kid gloves last ? What does 

 this suggest about the skin ? 



5. State a fact which shows that the skin gives out 

 offensive substances. 



6. State -a fact which shows that the skin is a protection. 



7. State a fact which shows 

 that the skin is a regulator of 

 temperature. 



8. Are wrinkles a sign that 

 the skin is too tight or too large 

 and loose for what it covers ? 



9. The loss of what tissue 

 causes wrinkles ? 



9. Hair. Sometimes a pa- 

 pilla, instead of being on the 

 surface of the dermis on a level with other papillae, is at 

 the bottom of a pit or bag called a follicle (Fig. 7). A 

 column of epithelial cells forming a hair grows from this 

 papilla, and the papilla is sometimes called the root of 





FIG. 6. Surface of the Palm, 

 magnified. 



Showing ridges and pores, or openings, 

 of the sweat glands. 



