The Digestive System: Overview Of The Digestive System

Overview of the Digestive System

The purpose of the digestive system is to hydrolyze macromolecules to their smallest subunits. The organs of the digestive system are located within the GI tract. The digestive track is made up of a series of hollow organs joined in a long, twisting tube from the mouth to the anus.

The process of digestion requires ingestion, digestion, movement, absorption, and elimination. All parts of the tract have four layers. These layers surround the lumen, or interior space of the GI tract.

Two “solid” digestive organs, discussed in the latter units of this chapter are the liver and the pancreas, produce digestive juices that reach the intestine through small tubes called ducts. The gallbladder stores the liver 's digestive juices until they are needed in the intestine. Parts of the nervous and circulatory systems also play major roles in the digestive system.

What Is Digestion?

Food and drink must be changed into smaller molecules of nutrients to be absorbed into the blood and carried to cells throughout the body. Digestion is the process by which food and liquid are broken down into smaller parts so that the body can use them to build and nourish cells, and to provide energy. Digestion involves the mixing of food, the movement of food through the digestive tract, and a chemical breakdown of large molecules of

The small intestine averages at about 6m. (18 ft.) in length, contains a wide range of enzymes to digest carbohydrate, protein, and fat content of food, 90% of the digestive system. Surface area of the intestine is approximately the size of a tennis court. Most of the enzymes are secreted by the pancreas and enter via a duct at the duodenum. Pancreatic amylase begins the digestion of carbohydrates. The wall of the intestine absorbs sugar, amino acid, glycerol, and fatty acids. Lactose intolerants do not have the brush border enzymes of the small intestine, which completes the