The meat, fruit, vegetables and grains you eat may be delicious and nourishing, but your body cannot benefit from food until it is digested. During digestion, the foods you eat and drink are broken down into smaller molecules by your digestive tract. Only then can nutrients be absorbed by the body to provide you with energy.
Digestive System
The digestive system consists of the digestive tract, or alimentary canal, and a number of other organs that also assist with digestion. Digestion begins in the mouth, as digestive juices in saliva begin chemically breaking down food. Your teeth and tongue also work to soften and moisten the food in preparation for swallowing. As you swallow, muscles in your mouth and throat move the mass of softened food into the upper esophagus, where rhythmic contractions of the esophageal walls then push it through to the stomach. This synchronized movement of the muscles all throughout the digestive tract is called peristalsis, according to the Mayo Clinic.
Stomach
The powerful muscles of the stomach further break down food into smaller pieces. The acidic environment of the stomach helps turn food into a semi-liquid paste called chyme. To accomplish this, the glands lining the stomach produce some 3 quarts of digestive fluids each day, according to the website Kids Health. The stomach propels the chyme through the pyloric valve a little at a time, into the first section of the small intestine, or duodenum.
Pancreas, Liver and Gallbladder
Other organs essential to digestion, the pancreas, liver and gallbladder, continue to process the chyme in a variety of ways. The pancreas releases enzymes that break down fats, carbohydrates and proteins. The liver performs hundreds of functions, serving to filter chemicals and process nutrients, storing and releasing them as needed; it also produces bile, which is stored in the gallbladder until it is needed during mealtime to dissolve fats, according to the National Digestive Diseases Information Clearinghouse.
Small Intestine
The second and third parts of the small intestine, the jejunum and the ileum, further continue food digestion until almost all the nutrients have been absorbed. Altogether, the small intestine measures some 20 feet in length, according to National Geographic. The small intestine is lined with tiny projections called villi, which move nutrients to the bloodstream.
Large Intestine
The remaining material is moved into the large intestine, which has the job of removing water from undigested matter and forming the remainder into a solid stool. The large intestine consists of the cecum, which serves as a transition from the small to large intestine; the colon, where harmless bacteria digest any remaining food; and the rectum, which stores the stool until it is released through the anus in a bowel movement.
