Question: how big are eustachian tubes?
Answer: In anatomy, the Eustachian tube, also known as the auditory tube or pharyngotympanic tube, is a tube that links the nasopharynx to the middle ear, which it is also part of. In adult humans, the Eustachian tube is approximately 35 mm (1.4 in) long and 3 mm (0.12 in) in diameter.