There are two kinds of organs that make up the digestive tract are the mouth, esophagus, stomach, small intestine, large intestine also called the colon - rectum, and anus all of which are hollow. Inside these hollow organs is a lining called the mucosa. In the mouth, stomach, and small intestine, the mucosa contains tiny glands that produce juices to help digest food. The digestive tract also contains a layer of smooth muscle that helps break down food and move it along the tract. There’re two “solid” digestive organs, the liver and the pancreas, both of which produce digestive juices (bile and insulin) that reach the intestine through small tubes called ducts. The gallbladder stores the liver's digestive juices (bile) until they are needed in the intestine. Parts of the nervous and circulatory systems also play major roles in the digestive system.
Digestion is important because when you eat foods such as bread, meat, and vegetables they are not in a form that the body can use as nourishment. Food and drink must be changed into smaller molecules of nutrients before they can be absorbed into the blood and carried to cells