Question
The distance between tympanic membrane and medial wall of middle ear at the level of center is:
| A. |
3 mm
|
| B. |
4 mm
|
| C. |
6mm
|
| D. |
2 mm
|
Show Answer
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Correct Answer » D
Explanation
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|
The middle ear cavity (tympanic cavity) is the space between the tympanic membrane laterally and the medial wall of the middle ear (formed mainly by the promontory of the cochlea) medially.
At the level of the center of the tympanic membrane (umbo), the distance between the tympanic membrane and the medial wall is approximately 2 mm.
This narrow space is important because:
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The handle of the malleus is attached to the tympanic membrane.
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The stapes footplate lies close to the oval window on the medial wall.
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Surgical procedures like myringotomy or tympanoplasty must consider this small distance to avoid damaging middle ear structures.
