What Are The Two Main Functions Of The Eustachian Tube?

What Are The Two Main Functions Of The Eustachian Tube? The Eustachian tube has three primary functions: 1) ventilation of the middle ear so that ambient pressure and middle ear pressure are similar; 2) protection of the middle ear from reflux of nasopharyngeal secretions and bacterial flora; and 3) drainage of secretions from the middle