middle ear

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middle ear

the sound-conducting part of the ear, containing the malleus, incus, and stapes

Middle Ear

 

in man and other terrestrial vertebrates, the part of the auditory system located between the external ear and the internal ear. The middle ear includes the air-filled tympanic cavity, which contains auditory ossicles and the auditory, or eusta-chian, tube. In man and some primates, it also includes mastoid cells. In most vertebrates, it is bounded on the outside by the tympanic membrane. The middle ear is separated from the internal ear by the cartilaginous or bony wall of the vestibule of the labyrinth. The auditory ossicles transmit sound vibrations from the tympanic membrane to the internal ear. In most animals, the middle ear is connected to the pharynx by the auditory tube. In many terrestrial vertebrates and especially in mammals it contains many additional structures that perform important acoustic functions. The middle ear is partly or completely reduced in many terrestrial and secondarily aquatic amphibians, in many mammals, and in some turtles and snakes.

middle ear

[′mid·əl ′ir]
(anatomy)
The middle portion of the ear in higher vertebrates; in mammals it contains three ossicles and is separated from the external ear by the tympanic membrane and from the inner ear by the oval and round windows.
References in periodicals archive ?
On initial investigation at our department, a hemorrhagic granulation-like tumor in the left middle ear cavity was revealed (Figure 1).
Due to vascularity of the mucosa in the middle ear cavity and diffusion characteristics of the gas, MEP can be affected by the changes in the tympanomastoid cavity volume.
In preoperative CT scans of the patient, some soft tissue density and aeration loss was observed in mastoid cells, but as our initial diagnosis was chronic otitis media and we did not observe any signs of cholesteatoma in the middle ear cavity and attic region after clearance of the polypoid mass, we did not explore the mastoid region.
In our series, non-dependent, homogeneous and polypoidal soft tissue densities were present in the mastoid antrum and middle ear cavity. In some of our cases (n=7), soft tissues occupied all spaces at the time of CT study with antral expansion, abutting the ossicular chain and bulging into the external auditory meatus.
An extensive array of tumors can occur in the middle ear cavity which can cause CHL by interfering with normal ossicular movement.
[5,6] The hallmarks of the cholesteatoma are the presence of non-dependent soft tissue density in middle ear cavity, ossicular erosion, smooth erosions of the middle ear borders and adjacent structures.
The coil was attached to the wall of the middle ear cavity and the magnet was fixed to the long process of the IN.
It seems to minimize static air pressure differences between the ear canal and middle ear cavity by the passive movement of the membrane toward the side of lower air pressure.
The condition occurs because an infection of the nose or throat passes along the eustachian tube from the back of the nose to the middle ear cavity. A child's eustachian tube is shorter than those of adults, making it easier for infectious agents to come in contact with the tube and reach the middle ear.
Instead, these animals use a "pressure-gradient system." In humans--and other mammals whose middle ear cavity is separated from the outside world by bone --sound usually strikes the eardrum from the outside only.
The typical CT findings of cholesteatomas are a soft-tissue mass in the middle ear cavity with varying levels of destruction [2, 3, 7, 11].
When this soft tissue is present with widening of the middle ear cavity, aditus ad antrum and loss of it "figure-of-eight" appearance, it increases the likelihood of a diagnosis of cholesteatoma.