The oesophagus (or esophagus) is also called the gullet. It is the part of the gastrointestinal system between the mouth and the stomach. It connects the pharynx and the stomach. It is about 25 centimetres (9.8 in) long. it passes through the thoracic cavity, pierces the diaphragm and leads to the stomach.
The oesophagus is lined with muscle. This muscle pushes food 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. mucous secreted by the epithelial cells in the inner lining helps in the smooth passage of food. 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.