Digesting means breaking food down into little pieces, so little that you canít see them with your eyes, so that your body can take those pieces and use them for energy and for building its own cells, tissues, and organs.
When you take a bite of food, your tongue tastes it and tells your brain. Then the brain sends an order to the parts of the mouth called the salivary glands. The salivary glands make a watery liquid called the saliva. The saliva helps make the food wet and soft and it has chemicals that help to digest the food. When you bite the food, the piece in the mouth is still too big to swallow. So you chew it up. The teeth cut, munch, and crunch the food into smaller and smaller pieces. Then you swallow the food down your throat, through a tube called the esophagus and into your stomach. The stomach is a big muscle designed to stir up the food that you eat. As it stirs, it adds liquids and chemicals to help digest the food.
From the stomach the food moves to the intestines. The intestines are a long, coiled up tube that winds around inside your belly. Most of the intestine is like a narrow rope. This is called the small intestine. The last part of the tube is bigger. This is called the large intestine. In the small intestine, the soupy food is mixed with more liquids and chemicals that break down the food into bits too small to see.
The good particles called the nutrients are then absorbed into the blood. The blood carries the nutrients to all the cells of the body. As the blood passes through the body it also goes through another organ in the digestive system, the liver. The work of the liver is to clean the blood. It also send liquids and chemicals to the small intestine to help digest the food eaten.
But some of the food is left over in the small intestine and cannot be digested. It gets passed on to the large intestine. Here, water is absorbed into the blood. The solid waste that is left behind goes out of the body through the anus when you use the toilet.
You also get rid of the liquid your body canít use. The blood carries good healthy nutrients all through the body. But the blood also carries waste away from the cells of the body. As the blood flows, it goes through two organs called the kidneys. The kidneys help clean the blood by separating the blood from the watery liquid you canít use, called urine.
The urine then goes out of the kidneys and into a little bag in the body called the bladder. When you go to the bathroom, you push the urine out of the bladder through a little tube called the urethra.
Directions: Answer the following questions. Describe the human digestive system in your own words.