How is food moved through the entire digestive system? What muscles help regulate the movement of food through the system?
Food is moved along though the digestive tract by the process of peristalsis. The circular muscles of the digestive tract tubes, i.e. the esophagus, small intestine, and large intestine, contract in waves which push food through the tubes. Movement of food is regulated by ringed muscles, called sphincters, one of which is located between the esophagus and the stomach, one between the stomach and the small intestine, and one between the large intestine and the exterior. When the sphincters, which are normally closed in order to prevent food from re-entering the previous chamber or tube of the tract, come into contact with food, they are stimulated to open and to allow the passage of food through to the next part of the digestive tract.
