. Elementary physiology . Fig. 115.—Diagrammatic view from before of the parts composing the organ of hearing of the left side. (After Arnold.) The temporal bone of the left side, with the accompanying soft parts, has been detached from the head, and a section has "been carried obliquely through it so as to remove the front of the meatus externus, half the tympanic membrane, and the upper and anterior wall of the tympanum and Eustachian tube. The meatus internus has also been opened, and the bony labyrinth exposed by the removal of the surrounding parts of the petrous bone, i, the pinna a
. Elementary physiology . Fig. 115.—Diagrammatic view from before of the parts composing the organ of hearing of the left side. (After Arnold.) The temporal bone of the left side, with the accompanying soft parts, has been detached from the head, and a section has "been carried obliquely through it so as to remove the front of the meatus externus, half the tympanic membrane, and the upper and anterior wall of the tympanum and Eustachian tube. The meatus internus has also been opened, and the bony labyrinth exposed by the removal of the surrounding parts of the petrous bone, i, the pinna and lobule; 2 to 2', meatus externus; 2', membrana tympani ; 3, cavity of^ the tympanum; above 3, the chain of small bones ; 3', opening into the mastoid cells ; 4, Eustachian tube ; 5, meatus internus, containing the facial (uppermost) and auditory nerves ; 6, placed on the vestibule of the labyrinth above the fenestra ovalis ; a, apex of the petrous bone ; b, internal carotid artery ; c, styloid process ; d, facial nerve issuing from the stylo-mastoid foramen ; e, mastoid process ; /, squamous part of the bone. serve to convey with diminished amplitude and somewhat modified the vibrations of the tympanic membrane to the internal ear, where they produce an effect on the endings of the auditory nerve. The auditory ossicles are kept in position by certain slender ligaments attached to the bony walls of the tympanum, and their tension and that of the tympanic membrane is adjusted by certain tiny muscles. The most external of the three ossicles, which is termed the malleus, from a supposed resemblance to
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Keywords: ., bookcentury1800, bookdecade1890, bookpubli, booksubjectphysiology
