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Eustachian Tube Function

Eustachian tube function includes ventilating the middle ear space. This means, it helps the pressure in the ear to remain normal. Learn more about Eustachian tube function and dysfunction.
Batul Nafisa Baxamusa
Last Updated: Jan 5, 2019
Although the name sounds complicated, Eustachian tube is actually an auditory tube that helps connect the pharynx to the middle ear. Also called pharyngotympanic tube, it is a part of the middle ear. Eustachian tube is named after an Italian anatomist of the 16th century, Eustachius.
The length of the tube is about 35 mm with about 3 mm diameter in an adult human. About 2/3rd of the tube is supported by cartilage and the last 1/3rd part of the tube is made up of bone. The function of the Eustachian tube is very important as it allows the eardrum to function properly. Have a look at the Eustachian tube function and dysfunction in detail.
Function of the Eustachian Tube
There are two important Eustachian tube functions. The first one includes ventilation of the middle ear space. This means, it helps the middle ear to remain at the normal ear pressure. The Eustachian tube is normally closed, but it opens up a little and allows a small amount of air to pass through.
This is done without any damage to the pressure between the middle ear and atmosphere around. The closed Eustachian tube is very important as it helps prevent ear infections due to the normal secretions from the back of the nose. Eustachian tube opens up by normal activities like yawning, swallowing, chewing gum, etc. 
When the Eustachian tube opens up, it helps in equalizing the atmospheric pressure with the pressure in the middle ear. When the Eustachian tube closes, it helps in relieving the pressure fluctuations and loud sounds in the ear. 
Apart from maintaining pressure, Eustachian tube helps in draining out mucus that gets accumulated in the middle ear. Swallowing and yawning helps in contracting the muscles at the back of the throat and palate. This helps in opening and closing of the Eustachian tube and draining away the mucus in the middle ear.
Dysfunctional Eustachian Tube
When one suffers from abnormal Eustachian tube functions, it leads to many pathological changes within the middle ear. These changes lead to many complications, including loss of hearing. The ear becomes vulnerable to recurrent acute otitis media and otitis media with effusion.
There are many people who are born with a dysfunctional Eustachian tube. Here the tube is narrower than it normally is and causes mucus accumulation. Thus, the person may have an impaired hearing along with otitis media with effusion. The mucus in this case becomes very thick and leads to a condition called glue ear. 
A long-term dysfunction of the Eustachian tube is generally seen in children. This is because the Eustachian tube is very small after birth. It is made of an immature cartilage that holds it in shape. Thus, children are vulnerable to Eustachian tube dysfunction than adults.
A dysfunctional Eustachian tube may remain open at all times. Such a tube is called 'patulous' Eustachian tube. This is a very rare condition that causes the patient to suffer from chronic ear infections. In some patients, dysfunctional Eustachian tube may fail to regulate air pressure.
Partially or completely blocked Eustachian tube leads to ear popping and clicking. In children, it occurs as a tickling sensation in the ear. Few patients may even complain of moderate to severe pain. As the ear pressure in the middle ear falls due to poor function of the Eustachian tube, it leads to feeling of ear being full.
Sounds become muffled and difficult to hear. Gradually, a vacuum is created in the middle ear space and this causes the fluid from the nasal cavity to be pulled in. This leads to development of otitis media.
Even smoking can lead to reduction in Eustachian tube function and can cause dysfunction of this auditory tube. The ear specialist may advice a function test to see if the Eustachian tube is functioning normally. If not, the ear specialist will recommend treatments accordingly.