Tonsils are the small masses of flesh found in pairs at the back of the throats of many mammals. In humans the word is actually used to describe three sets of this spongy lymphatic tissue: the lingual tonsils, the pharyngeal tonsils and the more commonly recognised palatine tonsils.
The palatine tonsils are the oval bits that hang down from either side at the back of your throat – you can see them if you open your mouth wide in the mirror. Although the full purpose of the palatine tonsils isn’t yet understood, because they produce antibodies and because of their prominent position in the throat, they’re thought to be the first line of defence against potential infection in both the respiratory and digestive tracts.
The pharyngeal tonsils are also known as the adenoids. These are found tucked away in the nasal pharynx and serve a similar purpose to the palatine tonsils but shrink in adulthood.
Finally, the lingual tonsils are found at the back of the tongue towards the root where it attaches and, if you poke your tongue right out, you should be able to spot them. These are drained very efficiently by mucous glands and, as a result, they very rarely get infected.