Tonsils: Definition, anatomy & function

Tonsils are small organs in the back of the throat.

Profile view of a doctor peering into the open mouth of the patient while holding the patient's chin and placing a long cotton swab into the patient's mouth.
Tonsils are two fleshy organs that sit in the back of the mouth on either side of the throat.
(Image credit: Getty Images)

Tonsils are a pair of oval-shaped tissues that sit at the very back of the mouth on either side of the throat. These are called palatine tonsils and are usually what people refer to when they describe their tonsils. 

However, we have three other types of tonsils, too: the adenoid or pharyngeal tonsil that sits at the back of the naval cavity; a pair of tubal tonsils that sit at the bottom of the auditory canal; and a pair of lingua tonsils that sit at the root of the tongue. Together, all the tonsils make up Waldeyer’s tonsillar ring, according to Encyclopedia Britannica.

Kimberly Hickok
Live Science Contributor

Kimberly has a bachelor's degree in marine biology from Texas A&M University, a master's degree in biology from Southeastern Louisiana University and a graduate certificate in science communication from the University of California, Santa Cruz. She is a former reference editor for Live Science and Space.com. Her work has appeared in Inside Science, News from Science, the San Jose Mercury and others. Her favorite stories include those about animals and obscurities. A Texas native, Kim now lives in a California redwood forest. 

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