CHAPTER VII 



THE FUNCTIONS OF THE SKIN 



The importance of the skin is made apparent when one 

 considers that the destruction of a third of that cover- 

 ing is nearly always fatal. Primarily its function is pro- 

 tective, as is shown by its position between the easily in- 

 jured inner tissues and the outer world. It contains those 

 nerve terminals which give the inner consciousness warn- 

 ing against pain, pressure, heat or cold, sharp, rough or 

 otherwise injurious objects. It contains the sweat glands 

 which aid in the elimination of harmful matter and as- 

 sist in regulating the body temperature; and, in the fe- 

 male, through the mammary gland, it supplies nourish- 

 ment to the infant. 



Sweat, or Perspiration, is the secretion of the sweat 

 glands which are found in nearly every part of the SKHI, 

 though most abundant in the palms of the hands and 

 soles of the feet. The number for the entire body is es- 

 timated to be about two million. They are simple tubu- 

 lar glands, lined by columnar epithelium, usually coiled 

 and having a thin muscular coat surrounding the larger 

 ducts. The average quantity of sweat in twenty-four 

 hours is from 700 to 900 grams, though the amount va- 

 ries greatly with the temperature and moisture of the at- 

 mosphere and the exertion of the individual. It is a 

 thin watery fluid with a low specific gravity and an al- 

 kaline reaction, which contains chloride of soda, urea, 

 uric acid and various other organic bodies. The influ- 

 ence of profuse sweating on the amount of urine has al- 

 ready been stated. To a limited degree the skin, through 



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