The organs in the human digestive system begin with the mouth and end at the anus. Each organ has a specific duty in the process of changing food and drink into usable nutrients for the body. Different enzymes work in conjunction with the continual movement through the digestive tract to break down the molecules of nutrients for absorption into the blood stream and cells of the body.
Mouth and Esophagus
Digestion begins as soon as the thought or smell of food reaches the brain. Discovery Health states that saliva secreted in the mouth during the process of chewing contains enzymes that begin the chemical breakdown of the food. The tongue pushes the chewed food into the throat for swallowing and passage down the esophagus. The esophagus contracts and pushes the food in a downward motion into the stomach.
Stomach
Enotes, an online nursing encyclopedia, states that the purpose of the stomach is to store, mix and further breakdown the food contents for absorption into the body. The stomach, positioned between the esophagus and the small intestine, has a sphincter muscle at the top and the pyloric valve at the bottom to control the entrance and exit of contents. Gastric glands in the lining of the stomach produce pepsinogen and hydrochloric acid that aid in the digestive process. An alkaline mucous fluid protects the wall of the stomach from damage by the hydrochloric acid. Muscular contractions of the stomach push the contents through the pyloric sphincter and into the duodenum at the entrance of the small intestine.
Small Intestine
The small intestine portion of the digestive system includes the duodenum, jejunum and ileum. The Cleveland Clinic states that muscular contractions (peristalsis) move the food through the 22-foot tubular-shaped intestine as it mixes in the enzymes from the pancreas and the bile from the liver. The semi-solid content changes to a liquid form from the action of the bile and enzymes. The jejunum and ileum facilitate the absorption of nutrients from the liquid into the bloodstream. The remaining product moves into the large intestine.
Colon, Rectum and Anus
Merck Manuals, an online medical library, states that the role of the large intestine (colon) includes absorption of water from the content and the production of vitamin K. The large intestine contains many bacteria that continue the digestive process. The destruction of these bacteria by antibiotics or some diseases causes an imbalance leading to diarrhea. At the end of the colon is the rectum and then the anus, where the waste material is expelled from the body.
Liver and Pancreas
The liver and pancreas are essential organs to the digestive system. While not in the direct pathway of the food route, each secretes specific enzymes and digestive juices that enter the digestive tract. The enzymes produced by the pancreas break down the fat, carbohydrate and protein in the food. The bile released by the gallbladder works to dissolve the fatty content in the intestines.
