Good question. We had to send our roving scientist N. out to lunch to figure this one out. Actually, N. is from room 3 and did a lot of research on the topic of digestion. Be sure to look at the books in your library that Nannan has suggested. Here is N's answer.

First, as you probably know, you have to eat and chew the food. Then you swallow it. When you swallow the food, it goes through a narrow tube called the esophagus which leads to your stomach. Your stomach is a muscular bag. When the stomach muscles contract, the food moves around and mixes with acid and digestive juices produced by the 35 million glands on the lining of the stomach. This process also kills harmful bacteria.

Eventually, the food leaves your stomach as a thin paste and goes to your intestines. The human intestines are usually 3 metres long, but when a person dies, they stretch to 8.5 metres from losing their elasticity. There are the small intestines and the large intestines. The food you eat goes through the small intestine first. Most of the intestines consist of muscle fiber so that the intestines can work on the food that goes through them. The intestines mix the food with certain secretions and pass it along. In order to do this, the small intestines consists of countless loops. Each loop holds a bit of food, and works on it, churning and digesting it for about 30 minutes. Then it passes the food on to the next loop.

To help in the process of digestion, the wall of the small intestine contains about 20,000,000 glands. These glands send about 5 - 10 litres of digestive juices into the intestine. This soaks and softens the food so that when it gets to the large intestine it would be in a semi-liquid state. The wall of the intestine is not smooth and resembles velvet. It is covered with millions of tiny tentacle-like villi. The villi tells the glands when to pour out digestive juices and helps in digestion also.

Food that can't be digested by juices is digested in the large intestine by bacteria that live there. This is called putrefaction. Billions of bacteria break down coarser parts of the food and extract valuable materials that our body needs. After the food has been sent to the different cells of our body which gets all the material they need, the cells send back the waste products. All the liquid is then squeezed out of the waste products and by the time they leave our bodies they are dry. That is how we digest.

Books in the Library:

Ask the Librarian to show you the 612 area. You will find books on other parts of the human body. You can also look up digestive systems or a digest in the Encyclopedia.

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