CHAPTER XV 

 THE SKIN 



The skin is not ordinarily considered an organ of much 

 importance. It seems to be merely a covering for the body 

 and it is not at first easy to believe that the skin actively 

 functions. In reality, it is an important organ which performs 

 some of the most vital offices in the human body. There is 

 no part of the body which has more to do with one's comfort 

 than the skin; and there is almost no part whose sluggish or 

 improper functioning leads to more general unpleasantness or 

 is more liable to induce illness. 



STRUCTURE OF THE SKIN 



The skin is a sheet of tissue covering every part of the 

 surface of the body, except the eyeballs, and even these when 

 the eyes are closed; there are a few large openings through it 

 for the entrance and exit of solid matter. The skin is about 

 -j^- of an inch thick, but it varies considerably, being much 

 thicker on the soles of the feet and palms of the hands than 

 elsewhere. If a thin section of the skin is examined under a 

 microscope it will be seen to consist of two distinct layers, 

 an outer called the epidermis, and an inner called the dermis. 

 The epidermis is lifeless, save for a thin layer on its inner 

 surface, and can be cut without pain or bleeding; the dermis 

 is extremely sensitive, full of nerves, blood vessels and glands; 

 Fig. 112. 



The difference between a plump person and a slender one is 

 also manifest in the skin appearance generally, for in the former 

 much fat, called adipose tissue, is often present among the glands 

 and connective tissue of the dermis. 



228 



