Definition of Eustachian tube

Eustachian Tube:This tube extends from the middle ear to the nasopharynx. Its role is to protect, ventilate, and drain both the middle ear and mastoid area. It helps balance the air pressure in the middle ear with the external air pressure. When descending in an airplane, this tube opens, causing the ears to 'pop.' It's more challenging to push air into the middle ear than to release it, which explains why ear discomfort is more common during a plane's descent compared to takeoff. Blockage of the Eustachian tube can result in a middle ear infection (otitis media). The tube opens into the nasopharynx and measures about 17 to 18 mm in length; it is horizontal at birth. As it matures, it doubles in length and becomes inclined at a 45-degree angle in adults. Consequently, the nasopharyngeal opening in adults is significantly lower than the middle ear opening. In infants, the shorter and more horizontal Eustachian tube provides inadequate protection and drainage, increasing the risk of middle ear infections. As the tube lengthens and inclines with age, it becomes more effective in protecting, ventilating, and draining the middle ear. In adults, the tube is opened by two muscles: the tensor palati and the levator palati, while in children, only the tensor palati is functional. This tube, also referred to as the otopharyngeal or auditory tube, links the ear to the pharynx.

Medical Definition & Meaning