A text-book of the diseases of the ear and adjacent organs . inside. In the neighbourhood ofthe membrana tympani the convexity is turned into a considerable concavityi Fig, 9), which deserves notice, because it, in conjunction with the membran;itympani, the latter placed obliquely to the axis of the meatus, forms a space 8 CONSTRUCTION OF THE OSSEOUS MEATUS. (sinus of the external meatus, H. Meyer), in which small foreign bodies areoften lodged. A comparison of the lengths of the superior and inferior walls of the meatusshows that the superior wall extends farther outwards than the inferior, b
A text-book of the diseases of the ear and adjacent organs . inside. In the neighbourhood ofthe membrana tympani the convexity is turned into a considerable concavityi Fig, 9), which deserves notice, because it, in conjunction with the membran;itympani, the latter placed obliquely to the axis of the meatus, forms a space 8 CONSTRUCTION OF THE OSSEOUS MEATUS. (sinus of the external meatus, H. Meyer), in which small foreign bodies areoften lodged. A comparison of the lengths of the superior and inferior walls of the meatusshows that the superior wall extends farther outwards than the inferior, butthat the inferior (c) extends from 6-8 mm. nearer the middle line of the bodythan the superior (b). By this, as well as by the unequal lengths of theanterior and posterior walls, the oblique position of the membrana tympanito the axis of the meatus is caused : a fact which must be taken into considera-tion at the examination of the membrana tympani, as well as at operations. The anterior wall (Fig. 10, a), compared with the other, is thinner, and in b b. 9 b Fig. 9.—Perpendicular Section (front)through Osseous Meatus and Tym-panic Cavity. a, Squamous portion ; b, Superior wall ofthe osseous meatus ; b, Dura mater ; c, Inferior wall of the osseous meatus ; d, Meatus ; e, Membrana tympani withthe malleus ; /, Tympanic cavity (leftear).
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Keywords: ., bookcentury1800, bookdecade1890, booksubjecteardiseases, bookyear
