The Digestive System
Categories: WHY WE HAVE A STOMACH
Sources: A Handbook Of Health
How the Food Reaches the Stomach. Our body, then, has an opening,
which we call the mouth, through which our food-fuel can be taken in.
A straight delivery tube, called the gullet, or esophagus, runs down
from the mouth to a bag, or pouch, called the stomach, in which the
food is stored until it can be used to give energy to the body, just as
the gasoline is stored in the automobile tank until it can be burned.
The mouth opening is furnished with lips to open and close it and
assist in picking up our food and in sucking up our drink; and, as much
of our food is in solid form, and as the stomach can take care only of
fluid and pulpy materials, nature has provided a mill in the mouth in
the form of two arches, of semicircles, of teeth, which grind against
each other and crush the food into a pulp.
In this diagram the entire alimentary canal is shown enlarged, and the
small intestine greatly shortened, in order to show distinctly the
course of the food in the process of digestion.]
In the bottom or floor of the mouth, there has grown up a movable bundle
of muscles, called the tongue, which acts as a sort of waiter, handing
the food about the mouth, pushing it between the teeth, licking it out
of the pouches of the cheeks to bring it back into the teeth-mill again,
and finally, after it has been reduced to a pulp, gathering it up into a
little ball, or bolus, and shooting it back down the throat, through
the gullet, into the stomach.
The Intestines. When the food has been sufficiently melted and
partially digested in the stomach, it is pushed on into a long tube
called the intestine, or bowel. During its passage through this part
of the food tube, it is taken up into the veins, and carried to the
heart. From here it is pumped all over the body to feed and nourish the
millions of little cells of which the body is built. This bowel tube, or
intestine, which, on account of its length, is arranged in coils,
finally delivers the undigested remains of the food into a somewhat
larger tube called the large intestine, in the lower and back part of
the body, where its remaining moisture is sucked out of it, and its
solid waste material passed out of the body through the rectum in the
form of the feces.