Cross section of the thoracic part of the esophagus of a chicken (HE): overview (3)
The oesophageal tonsil is located at the transition between the thoracic part of the esophagus and the proventriculus.
The lymphoid tissue here is organized around the bottom and sides of the mucosal folds and forms tonsillar units. These units consist of a central crypt surrounded by a â€˜wallâ€™ of lymphoid tissue. In chickens 6 to 8 tonsillary units are formed.