Waldeyer's tonsillar ring

Lymph: Waldeyer's tonsillar ring
Regional lymphatics. Waldeyer ring labeled at center top.
Latin	anulus lymphoideus pharyngis

Waldeyer's tonsillar ring (or pharyngeal lymphoid ring) is an anatomical term describing the lymphoid tissue ring located in the pharynx and to the back of the oral cavity.

It was named after the nineteenth century German anatomist Heinrich Wilhelm Gottfried von Waldeyer-Hartz.

The ring consists of (from superior to inferior):

• Pharyngeal tonsil (also known as 'adenoids' when infected)
• Tubal tonsil (where the Eustachian tube opens in the nasopharynx)
• Palatine tonsils (commonly called "the tonsils" in the vernacular, less commonly termed "faucial tonsils")
• Lingual tonsils

There also normally is a good amount of mucosa-associated lymphoid tissue (MALT) present between these tonsils (intertonsillar) around the ring, and more of this lymphoid tissue can variably be found more or less throughout at least the naso- and oropharynx.

Some animals, but not humans, have one or two additional tonsils:

• Soft palate tonsil
• Paraepiglottic tonsil