THE PARTS OF THE SKIN
The pore P on the surface of the skin is the end of a tube through which sweat flows out. At O are the oil sacs that feed the hair H. At B are the little blood vessels that make the skin look pink.
The skin, you see, is made up of different layers. When you burn yourself, you can see a layer of skin stand out like a blister. It is white; but if the blister is broken, underneath you see the coat that is full of tiny blood vessels, so tiny and so close together that this whole coat looks red. The skin, like every other part of the body, is made up of tiny animal cells. In the outer coat they become quite flat like little scales and then wear off; and their places are taken by the newer cells that are growing from beneath. The skin grows from beneath, and bit by bit it sheds its old outer coat. This is how it keeps itself nice and new on the outside and “grows away” the marks of cuts and burns.
Now hold up your hand and look across it toward the light. What do you see? It looks fuzzy, doesn’t it? Ever and ever so many tiny little hairs are on it. The other day a little boy asked me what made his skin look so rough? I looked, and saw that all the little hairs were standing on end, so that his skin looked like “goose-flesh.” It was because he was cold. The muscles at the roots of the hairs had shortened, so that they pulled the hairs straight up and made the skin look rough.
What part of the body has a great deal of hair on it? The head, of course. Isn’t it strange that you have such long hair on the top of your head and none at all on the soles of your feet or the palms of your hands? The hair on your head protects you from cold and rain and the hot sun; but hair on your palms, would only be in the way.
Now look at the ends of your fingers. There the skin has grown so hard that it forms nails. If you look at your toes, you will see that the same thing has happened there. These nails are little pink shells to protect the ends of your fingers and toes. You see what a wonderful coat it is that you are wearing.
Does the skin coat keep you warm? Yes, and not only that, but it keeps you cool, too. You have often seen little drops of water on your skin, when you were very hot. This sweat, or perspiration, as we call it, cools the body by making the skin moist. You know how cold it makes you to be wrapped in a wet sheet. Well, the skin cools you in just the same way, when it becomes wet with sweat. The sweat comes from the blood under the skin; so that, as we saw before, by letting this moisture pass through, the skin acts as a sieve to let out the waste from the blood.
Then, too, the skin covers and protects all the other parts. It is thin where it needs to be thin, so as not to interfere with quick movements, as on the eyelids and the lips; and thick where it needs to be thick, to stand wear and tear, as on the soles of the feet and the palms of the hands. I remember once taking a sliver of shingle out of the back of a little boy who had been sliding down a roof. I had to sharpen my knife and press and push and at last get a pair of scissors to cut out the sliver. It was just like cutting tough leather. But even if we do sometimes get cuts and burns and bruises, yet our skin coat protects us far more than we really think. It keeps out all sorts of poisons and the germs of blood-poisoning and such diseases. These enemies can attack us only through a scratch or cut in the skin, for that is the only way they can get into the blood. The skin is better than any manufactured coat, too, because, if it is torn or scratched, it can mend itself.
READING BY TOUCH INSTEAD OF SIGHT