What is Waldeyer's ring?
Waldeyer’s ring is a complete ring of subepithelial lymphoid tissue present in and comprising of palatine tonsils, adenoids, lingual tonsils, tubal tonsils and the pharynx.
Parts of the Waldeyer’s ring :
1) Palatine tonsil
2) Nasopharyngeal tonsil (adenoids)
3) Lingual tonsil present on the posterior 1/3 of tongue
4) Tubal tonsil near the Rosenmuller’s fossa
5) Lateral pharyngeal bands
What is the importance of Waldeyer’s Ring ?
1) It is an important part of mucosal associated lymphoid tissue (MALT) which processes antigen and presents it to T-helper cells and B-cells.
2) This ring acts as a protective barrier for the lower respiratory tract
3) Waldeyer’s ring occupies the entry of air and food passage and is constantly exposed to new antigenic stimuli.
4) Production of immunoglobulins : The tonsillar tissue produces IgG, IgA and IgD. These immunoglobulins are secreted into pharynx and their output is increased in response to a wide variety of inflammatory processes.
5) The tissue of Waldeyer’s ring undergoes physiological hypertrophy during early childhood as the child is exposed to increasing amount of antigenic stimuli.
Regression : This lymphoid tissue reaches its maximum size by 10 years of age and then gradually regresses.