A text-book of the diseases of the ear and adjacent organs . he fibres of the cochlear nerve. Besides, there are, on the pos-terior wall of the meatus internus, a small group of openings for the passageof a few branches of the ramus vestibuli. 2. The Membranous Labyrinth. The membranous labyrinth, lying in the osseous capsule just described,consists of the saccules of the vestibule, the three membranous semicircularcanals, and the membranous portion of the cochlea. 590 THE SACCULES OF THE VESTIBULE. a. The Saccules of the Vestibule. Of the two saccules of the vestibule, the one connected with
A text-book of the diseases of the ear and adjacent organs . he fibres of the cochlear nerve. Besides, there are, on the pos-terior wall of the meatus internus, a small group of openings for the passageof a few branches of the ramus vestibuli. 2. The Membranous Labyrinth. The membranous labyrinth, lying in the osseous capsule just described,consists of the saccules of the vestibule, the three membranous semicircularcanals, and the membranous portion of the cochlea. 590 THE SACCULES OF THE VESTIBULE. a. The Saccules of the Vestibule. Of the two saccules of the vestibule, the one connected with the semicircularcanals (Figs. 297 and 298) is termed the utricle, and the other communicatingwith the canal of the cochlea the saccule. The utricle (5 to 6 mm. long),longish in form, is embedded in therecessus hemielhpticus, and communicatesimmediately with the semicircular canals by five foramina. It extends fromthe roof of the vestibule to the entrance of the lower ampulla, and runsfrom the anterior superior portion downwards and backwards. It is divided. Fig. 299.—Horizontal Section through the Vestibule above the FenestraOvalis of a New-born Infant. I, Utriculus ; a, Ampulla ext. and crista ampullaris discharging into it; /, Upperspace of the sacculus ; n, Nerve bundles of the ramus vestibuli, passing to theutriculus and the macula acust. utric. ; p p, Adherent wall of the sacculus ; p,Anterior wall of the sacculus ; n, Nerve bundles passing to the macul. ; an, Nerve anastomoses running from the bundle n to n. After a pre-paration in my collection. into three sections, of which the upper, called the recessus utriculi (Fig. 298,re), is 3 to 35 mm. in breadth and length, while the second and third por-tions are formed by the utriculus proprius, 3 mm. long and lfi to 2 The ampullae of the frontal and horizontal semicircular canals openinto the recessus utriculi, while the ampullae of the inner semicircular canal,the openings of the horizontal and the co
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Keywords: ., bookcentury1800, bookdecade1890, booksubjecteardiseases, bookyear
