A text-book of the diseases of the ear and adjacent organs . tra rotunda sive memb. tymp. secundaria Scarpce), somewhat 26 INNEK WALL OF THE TYMPANIC CAVITY. concave towards the menibrana tympani, is stretched out, which shuts out thecochlear canal from the tympanum. The height varies from 1*6 to 3 mm.,the width from 1 to 8 mm. Between the niche and theeminentia pyramidalisis a depression in the wall, varying in size in different individuals {Sinus ). Between and a little in front of the two fenestra?, the wall of the tym-panum is strongly bulged out towards the cavity; this
A text-book of the diseases of the ear and adjacent organs . tra rotunda sive memb. tymp. secundaria Scarpce), somewhat 26 INNEK WALL OF THE TYMPANIC CAVITY. concave towards the menibrana tympani, is stretched out, which shuts out thecochlear canal from the tympanum. The height varies from 1*6 to 3 mm.,the width from 1 to 8 mm. Between the niche and theeminentia pyramidalisis a depression in the wall, varying in size in different individuals {Sinus ). Between and a little in front of the two fenestra?, the wall of the tym-panum is strongly bulged out towards the cavity; this is due to the projectionof the first whorl of the cochlea, and is called the promontory. Verticallyabove it, in an open or covered groove, extends Jacobsons nerve, whichconnects the jugular ganglion with the n. petrosus superf. minor. A numberof inconstant winding furrows show the course of the nerve branches of theplexus tympanicus in the mucous membrane covering the promontory. Above and slightly behind the fenestra ovalis there is seen a portion of the. d h cFig. 26.—Inner Wall of the Tympanic , Fenestra ovalis with the stapes ; b, Fenestra rotunda ; c, Promontory ; (/, ; e, Canalis Fallopise ; /, Canal for the tensor tympani : g, Mastoidprocess. Fallopian canal, containing the facial nerve. The Fallopian canal commencesin the internal meatus, above the place where the auditory nerve enters thelabyrinth, passes then into the substance of the petrous bone above the vesti-bule towards the outer side, and, arrived at the inner wall of the tympaniccavity, forms a knee-like bend (Fig. 26), from which the canal continues back-wards along the inner wall of the tympanic cavity above the fenestra ovalis,and extends farther along the boundary between the posterior and the interiorwalls of the tympanum, with an abrupt bend downwards to the stylo-mastoidforamen. On the portion of the Fallopian canal extending above the fenestra ovalis,there is an elevation proj
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Keywords: ., bookcentury1800, bookdecade1890, booksubjecteardiseases, bookyear
