The alimentary canal is a sort of pathway all through the body. Along
this pathway, food travels from the time it is swallowed to the time the
unused part of it leaves the body as waste. Although it is called a
"canal," it is really a series of big and little pipes, all connected
together to form one tube about 30 feet long.
The alimentary canal is a sort of pathway all through the body. Along this pathway, food travels from the time it is swallowed to the time the unused part of it leaves the body as waste. Although it is called a "canal," it is really a series of big and little pipes, all connected together to form one tube about 30 feet long. It begins at the mouth and goes down through the neck and chest into the belly; there it winds around through the intestines and ends in a small opening at the back of the body called the anus. The entire alimentary canal is lined with a thin, moist skin called a mucous membrane. A good example of mucous membrane is the lining of the mouth and inside of the nose.
The digestion of food takes place in the different parts of the alimentary canal. After food is chewed and swallowed it passes through the pharynx, a tube about 4y2 inches long, and down into the esophagus, another tube about 9 inches long that connects with the stomach. The stomach is a pear-shaped bag about 11 inches long and 4 inches wide. In the walls of the stomach there are glands, or tiny sacs, that pour out liquids called digestive juices. These help break down the food. In the stomach the food is only partially digested.
It passes into the small intestine, a long narrow tube about 23 feet long, which takes up most of the belly or abdomen. It is in this long, winding tube that the digestion of food is completed. What remains of the food now passes on to the colon, or large intestine, which is a bigger but shorter tube than the small intestine. The last eight inches of the colon is called the rectum. The waste matter of the body is stored here until it is forced out of the anus.
