Waldeyer's tonsillar ring

Waldeyer's tonsillar ring
Regional lymphatics. Waldeyer ring labeled at center top.
Details
Latin	anulus lymphoideus pharyngis
Identifiers
TA
TH	{{#property:P1694}}
TE	{{#property:P1693}}
FMA	{{#property:P1402}}
Anatomical terminology [[[d:|edit on Wikidata]]]

Waldeyer's tonsillar ring (also pharyngeal lymphoid ring or Waldeyer's lymphatic ring) is an anatomical term collectively describing the annular arrangement of lymphoid tissue in the pharynx. Waldeyer's ring circumscribes the naso- and oropharynx, with some of its tonsillar tissue located above and some below the soft palate (and to the back of the oral cavity).

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

The ring consists of the (from superior to inferior):

• 1 (or two) pharyngeal tonsils (or nasopharyngeal tonsil(s), due to the location; also known as 'adenoid(s)' when inflamed/swollen) They are located on the roof of the nasopharynx, under the sphenoid bone.
• 2 tubal tonsil (bilaterally, where each Eustachian tube opens into the nasopharynx) (Usually develops from an accumulation of lymphoid tissue in the pharyngeal tonsil)
• 2 palatine tonsils (commonly called "the tonsils" in the vernacular, less commonly termed "faucial tonsils"; located in the oropharynx; also see tonsillitis and tonsillectomy)
• 1 (or many) lingual tonsils (on the posterior tongue)

There also normally is a good amount of mucosa-associated lymphoid tissue (MALT) present between all 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