Anatomy and Microanatomy of Tonsils
The tonsils are the immunological guardians of the upper aerodigestive tract. They are a first line of defense and involved in antimicrobial immunity, immune exclusion, and oral tolerance. During embryogenesis the developments of the branchiogenic arcs, the aerodigestive tract, and the thymus are closely related and the function is detectable early. The proximity and interaction of lymphoepithelium (or follicle associated epithelium) intraepithelial, innate, and adaptive lymphoid cells reveal a blueprint of MALT (mucosa associated lymphoid tissue) however, the tonsils are highly specialized secondary lymphatic organs that resemble lymph nodes without afferent lymphatic vessels and are part of the integrated mucosal immune system. The aim of the article is to provide anatomical and functional overview of Waldeyer's ring of tonsils.