Eustachian tube connects middle ear and pharynx. It equalises air pressure in the middle ear to outside. It also drains the mucus of the middle ear.
Eustachian tube is an auditory tube, which connects the middle ear and the nasopharynx. As the middle ear is not in direct contact to the outside, so there are chances of building up the pressure difference. The Eustachian tube equalizes the pressure on the tympanic membrane.
Normally the eustachian tube remains collapsed but it opens while swallowing, chewing, yawning, etc. When there is a sudden change in the pressure, e.g. during air travel, scuba diving, etc. our ears get blocked for some time. These activities such as chewing gum are advised so that the air passes through the eustachian tube between the nasopharynx and the middle ear and the air pressure is equalised.
If the eustachian tube does not open in these circumstances, it causes discomfort, ringing sound, dizziness, etc.
The Eustachian tube also drains the mucus of the middle ear. During nasal congestion, allergies and upper respiratory tract infection, the membrane of its opening gets swollen leading to trapping of fluid and clogging. This results in the growth of bacteria and causes ear infection.
This was in brief about the Eustachian Tube Function. Get access to all the NEET Questions with explanations, only at BYJU’S.