Eustachian tube

(redirected from Eustachio, Bartolommeo E.)
Also found in: Dictionary, Thesaurus, Medical.

Eustachian tube

(yo͞ostā`shən) [for Bartolomeo EustachiEustachi, Bartolomeo
, d. 1574, Italian anatomist. He lived in Rome from 1549 and taught at the Collegia della Sapienza (later the Univ. of Rome). He described many structures in the human body, including the Eustachian tube of the ear, the adrenal glands, the thoracic duct, the
..... Click the link for more information.
], a hollow structure of bone and cartilage extending from the middle earear,
organ of hearing and equilibrium. The human ear consists of outer, middle, and inner parts. The outer ear is the visible portion; it includes the skin-covered flap of cartilage known as the auricle, or pinna, and the opening (auditory canal) leading to the eardrum (tympanic
..... Click the link for more information.
 to the rear of the throat, or pharynx, technically known as the pharyngotympanic or auditory tube. By permitting air to leave or enter the middle ear, the tube equalizes air pressure on either side of the eardrum. The tube can become blocked, as by enlarged adenoids or the mucous secretions of a cold, so that external and internal pressure become imbalanced. Earache and diminution of hearing may result. The tube may also serve as a pathway to the ear for infections of the throat. A common ear disease known as otitis media, usually appearing in early childhood, is thought to be related to the Eustachian tube. The tube tends to be shorter and more horizontal among children, factors which facilitate the spread of infections from upper respiratory diseases to the middle ear, as well as the accumulation of fluids in the region.
The Columbia Electronic Encyclopedia™ Copyright © 2013, Columbia University Press. Licensed from Columbia University Press. All rights reserved. www.cc.columbia.edu/cu/cup/
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Eustachian Tube

 

auditory tube, in terrestrial vertebrates, the canal that unites the pharynx with the cavity of the middle ear; named for B. Eustachio, who first described it in 1563.

The eustachian tube serves to equalize the air pressure in the middle ear with that of the surrounding environment. It originates from the rudiment of the gill slit. In crocodiles it forms a complex system of anastomosing canals. It is absent in snakes because of the reduction of the middle ear.

In man, the eustachian tube is a tubular formation that unites the nasopharynx with the tympanic cavity of the middle ear. Air enters the tympanic cavity through the eustachian tube from the nasopharynx. When the eustachian tube is inflamed, the entry of air into the tympanic cavity often ceases or is limited, producing a sensation of noise and congestion in the ear; hearing is somewhat decreased.

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.

eustachian tube

[yü′stā·shən ‚tüb]
(anatomy)
A tube composed of bone and cartilage that connects the nasopharynx with the middle ear cavity.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.

eustachian tube

eustachian tubeclick for a larger image
The Eustachian tube is normal in the case on the left. In the case on the right, it is blocked. The subject is likely to suffer from pain and injury in case he/she flies with sinus congestion resulting in the eustachian tube getting blocked.
The tube connecting the middle ear to the breathing passage. A person suffers from an earache if this tube is blocked and the aircraft is descending. The tube opens automatically and equalizes the pressure across the middle ear while climbing. It also opens during descent when a person swallows, yawns, or carries out the Valsalva maneuver. The eardrum can be perforated or damaged if the eustachian tube is blocked (as in congestion) and the aircraft descends rapidly. This is caused by the very high differential pressure inside the ear and the atmosphere. See also Valsava maneuver.
An Illustrated Dictionary of Aviation Copyright © 2005 by The McGraw-Hill Companies, Inc. All rights reserved

Eustachian tube

a tube that connects the middle ear with the nasopharynx and equalizes the pressure between the two sides of the eardrum
Collins Discovery Encyclopedia, 1st edition © HarperCollins Publishers 2005