Waldeyer’s ring is a collection of lymphoid tissue or follicles in the upper part of digestive system. This ring is formed by: Superiorly- Pharyngeal tonsils or Adenoids. Inferiorly- Lingual tonsil. Laterally- Palatine tonsils and tubal tonsils. I. Pharyngeal Tonsil: Lie postero superiorly under the mucous membrane of the roof and adjoining posterior wall of nasopharynx. […]