Cells in the small intestine help digested food pass through the intestinal lining into the bloodstream. The cells in the lining of the stomach and small intestine produce and release hormones that control the function of the digestive system. These hormones stimulate production of digestive juices and regulate appetite.
Digestion works by moving food through the gastrointestinal tract and is important for breaking food down into nutrients, which the body uses for energy, growth and cell repair. As food passes through the GI tract, it mixes with digestive juices, causing large molecules of food to break down into smaller molecules. The process of digestion begins in the mouth and ends in the small intestine.
The small intestine absorbs most digested food particles, water and minerals, and passes them on to other parts of the body. Digestive juices contain enzymes that break food down into different nutrients, which the body stores until needed, or they undergo further chemical changes.