File:Eustacian tube angle.jpg

Newborn to adult auditory tube

Auditory tube = Eustachian, otopharyngeal or pharyngotympanic tube.

Connects middle ear cavity to nasopharynx portion of pharynx

Ventilation - pressure equalization in the middle ear

Clearance - allow fluid drainage from the middle ear Tube is normally closed and opened by muscles

At birth - shorter (17-18 mm), narrower and runs almost horizontal Tube is opened by a single muscle, tensor palati muscle

Adult - longer (twice as long), wider and runs at approximately 45 degrees to the horizontal. Tube is opened by two separate muscles, tensor palati and levator palati

Reference

<pubmed>17364173</pubmed>