The Food Journey

This article is a supplement to the article on the digestive system

Food travels through the digestive tract because its walls have muscles that contract and push it. If the contractions reverse their direction, the food recedes, rather than advances, and can cause vomiting.

Throughout the digestive tract, there are different structures that control the advancement of food. The first is called the epiglottis and is located between the pharynx and the esophagus. It is like a lid that closes the pharynx when we swallow.

Then, between the esophagus and the stomach, there is a sphincter, that is, a ring of muscle, called the cardia. This closes the exit of food from the stomach when it is being processed inside. Between the stomach and the small intestine, there is another sphincter, the pylorus, which remains closed while the Food is in the stomach, but after several hours, it relaxes (opens) and allows it to pass into intestine.

Between the small intestine and the large intestine, is the ileocecal valve. The valves function as doors that are pushed open from one side and close automatically. Thus, the food that passes through the ileocecal valve cannot back up. At the outlet of the digestive tract, there is the anus, which is a sphincter.