The oesophagus, unlike other parts of the gastrointestinal tract, lacks a serosa. The serosa is the outermost layer of the digestive system, composed of a thin layer of epithelial cells and a layer of connective tissue. Its presence helps in the smooth movement of organs within the abdominal cavity.
The oesophagus, however, is situated in the mediastinum and does not require a serosa for its function. Instead, it has an adventitia, which is a layer of connective tissue that anchors the oesophagus to surrounding structures.
