You probably recognize your tonsils as the two marble shaped lumps located at the front of your throat. Maybe you're one of the less than 0.2% of people that have had them removed! We use the word 'tonsil' to describe a bundle of nodes associated with the throat.
As well as the two lumps we call 'palatine' tonsils you can see in your throat you have others too, that form a ring immune surveillance tissue around one of the major entry points of your body - the mouth!
Specialized cells sit on the surface of these node bundles that catch and process antigens as they pass by. Fragments of these antigens are then presented to B and T cells deeper within the nodes themselves to trigger the necessary immune responses.
The pharyngeal tonsil or 'adenoid' sits at the back of the nasopharynx above the soft palate (the nasopharynx is the space above the back of your throat that joins the nasal cavity).
These nodes lie close to the torus tubarus, an anatomical feature that lies between the throat and the ear. The tonsils have a role in immune surveillence between these two organs due to their anatomical connection.
Lingual tonsils are located at the very base of the tongue at the back of the mouth. Swelling of these tonsils can worsen the symptoms of sleep apnea in affected individuals.
These are the node bundles that you can see on either side of your throat. When you get tonsillitis, or an infection of the tonsils, these nodes can swell considerably. In serious cases they can cause partial occlusion ('closing up') of the throat, affecting a person's ability to feed and breathe.