Digestion facts

   Our bodies are built of many millions of living cells. Every one of these cells needs food. The cells in our fingers need food just as much as the cells in the walls of our stomachs. The blood carries food to them all. Before the food we eat can get into the blood it must be changed to a liquid. The changing is called digestion.
   Many parts of the body have a share in digesting our food. All together they are called the digestive system. The diagram at the right shows the digestive system. It takes several different digestive juices to change all the kinds of food we eat into liquids. One of these juices is saliva. Saliva comes into our mouths from nearby glands and is mixed with the food as we chew.
   When the food reaches the stomach, it is mixed with gastric juice, which comes from the stomach walls. Then in the small intestine three other juices help with diges­tión. They are bile, pancreatic juice, and intestinal juice. Bile comes from the liver. Pancreatic juice comes from the pancreas. Intestinal juice comes from the wall of the small intestine.
   By the time the food has traveled through the small intestine, all of it has been digested that is going to be. It has soaked through the walls of the blood vessels in the wall of the intestine. The waste goes into the large intestine and then out of the body.
   Other animals must digest their food, too. But most of them do not eat nearly as many kinds of food as we do.