Video : https://youtu.be/d_b2jQlG59w
1. Description and function of the esophagus
The oesophagus is a duct used to carry food from the mouth to the stomach, starting from the pharynx and ending in the stomach, through the diaphragm (Figure 1). The inside of the oesophagus is always lubricated. After swallowing, the sphincter at the upper edge of the oesophagus closes, the circular and longitudinal muscle layers of the oesophagus create the peristalsis pushing the food towards the lower edge of the oesophagus where the lower sphincter (sphincter Barrett) is located, the latter opens to let the food enter the stomach; this sphincter also prevents any reflux from the stomach to the oesophagus.