Oesophagus

Oesophagus in the gastrointestinal system

The oesophagus (also spelled esophagus), also called the gullet, is the part of the gastrointestinal system between the mouth and the stomach.

The oesophagus is lined with muscle. This muscle pushes the food bolus (ball) down into the stomach. The oesophagus can contract or expand to allow for the passage of food. The muscular movement that pushes the food down the oesophagus is called peristalsis. At the entrance to the stomach there is a ring of muscle called a sphincter. This is usually closed, but relaxes as food approaches, allowing it to enter the stomach. In the stomach, the food is churned until it turns into a soupy mixture called chyme.

It is therefore adapted for transport rather than for digestion or adaptation.