Anatomy and Cell Biology 3319 Lecture : Anatomy Notes
Document Summary
The gi tract is also called the alimentary canal. The upper digestive (gi) tract consists of the mouth, pharynx, esophagus, and stomach, and these structures are involved in ingestion and digestion. The lower digestive (gi) tract consists of the small intestine, large intestine, and rectum/anus, and these structures are involved in absorption and defecation. Ingestion is the taking of food into the mouth. Digestion is the breaking down of food and it can be mechanical (chewing) or chemical (enzymes). Absorption occurs mainly in the small intestine and it is the transportation of nutrients from food into the blood. Defecation is the removal of indigestible substances from the body as feces. The oral stage involves the movement of food from the mouth to the oropharynx (which is located right behind the oral cavity). The pharyngeal stage moves food from the oropharynx to the esophagus.