Lymphoepithelial organ

A lymphoepithelial organ is an organ of the lymphatic system , the basic structure of which is formed by an epithelium . The lymphoepithelial organs include the tonsils of the Waldeyer pharyngeal ring (tonsilla pharyngea, tonsilla palatina, tonsilla lingualis, tonsilla tubaria), the thymus and the bursa Fabricii . In the other lymphatic organs, on the other hand, the basic structure is formed by a reticular connective tissue ( lymphoreticular organ ).

In the tonsils, the lymphatic tissue collects directly under the depressions ( crypts ) of the epithelium. When lymphocytes cross over ( leukodiapedesis ), the epithelium loosens, which in the case of massive diapedesis almost takes on a reticular appearance ("dedifferentiation"). The thymus differs from the other lymphoepithelial organs in that during organogenesis the endodermal epithelium of the gill intestine is detached and displaced. The epithelial association dissolves and an "epithelial reticulum" is created. The thymus also has an organ capsule .

Individual evidence

^ Keith M. Dyce, Wolfgang O. Sack, CJG Wensing: Textbook of Veterinary Anatomy . 4th edition. Elsevier Health Sciences, 2009, ISBN 978-1-4377-0875-2 , pp. 812 .
↑ Johannes W. Rohen: Histological differential diagnosis: Instructions for the diagnosis of histological preparations . Schattauer, Stuttgart 1994, ISBN 978-3-7945-1676-6 , pp. 61 .

[1] Keith M. Dyce, Wolfgang O. Sack, CJG Wensing: Textbook of Veterinary Anatomy . 4th edition. Elsevier Health Sciences, 2009, ISBN 978-1-4377-0875-2 , pp. 812 .

[2] Johannes W. Rohen: Histological differential diagnosis: Instructions for the diagnosis of histological preparations . Schattauer, Stuttgart 1994, ISBN 978-3-7945-1676-6 , pp. 61 .