Eustachian tube

A tube which runs from the middle ear to the back of the throat.  It usually allows the middle ear to be kept full of air, which means the ears can work properly.  However, if the eustachian tube becomes blocked, air cannot enter the middle ear and the cells lining it begin to produce fluid. This makes it harder for sound to pass through to the inner ear, and is known as glue ear (otitis media).

 

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