The middle ear cavity is connected to the nasal cavity through a canal called the Eustachian tube. The main function of the Eustachian tube is to provide ventilation and drainage of the middle ear. If the mouth of the Eustachian tube is clogged with an enlarged adenoid, drainage becomes difficult, and because the Eustachian tube is more horizontal in children, it makes it easier for the microbes in the nasal passages to reach the middle ear.
