Expansion
A ring of guards around the throat
Mnemonic
“Four tonsils make a ring”, from top to bottom:
- Pharyngeal tonsil (adenoids), in the nasopharyngeal roof
- Tubal tonsils, around the Eustachian tube openings
- Palatine tonsils, the ones removed in tonsillectomy
- Lingual tonsil, on the posterior third of the tongue
It is a ring of mucosa associated lymphoid tissue guarding the entrance to the respiratory and digestive tracts.
The palatine tonsil bed lies on the superior constrictor, with the glossopharyngeal nerve just deep to it, which is why tonsillectomy can cause referred ear pain and transient taste change, and why the external palatine (paratonsillar) vein is the usual source of secondary haemorrhage.
Expansion
- Lingual tonsil - tongue base
- Palatine tonsils - sides of the oropharynx
- Tubal tonsils - around the eustachian tube openings
- Pharyngeal tonsil - roof of the nasopharynx, the adenoid