The digestive tract is the system of organs that takes in food, digests it to extract energy and nutrients, and expels the remaining waste. The major functions of the GI tract are ingestion, digestion, absorption, and defecation. In a normal human adult male, the GI tract is approximately 20 feet long and consists of the upper and lower GI tracts.

The upper GI tract consists of the mouth, pharynx, esophagus, stomach and first part of the small intestine. The lower GI consists of the small intestine, large intestine and the rectum.

Click here to see a drawing of the tract.