The essentials of healthA text-book of anatomy, physiology, hygiene, alcohol, and narcotics . Fig. 112. The three bones of the middleear: H, the hammer, or malleus; a, the an-vil, or incus; s, the stirrup, or stapes. THE SENSE OF HEARING. 319 the stirrup ; thus a chain of bones is established fromthe tympanic membrane across the cavity of the middleear. The outer end of this bony chain is attached to amembrane, and so is the inner end. Beneath the innermembrane, just opposite the stirrup, in the inner ear, is. Fig. 113. The middle and inner ears, from a different view and on alarger scale than
The essentials of healthA text-book of anatomy, physiology, hygiene, alcohol, and narcotics . Fig. 112. The three bones of the middleear: H, the hammer, or malleus; a, the an-vil, or incus; s, the stirrup, or stapes. THE SENSE OF HEARING. 319 the stirrup ; thus a chain of bones is established fromthe tympanic membrane across the cavity of the middleear. The outer end of this bony chain is attached to amembrane, and so is the inner end. Beneath the innermembrane, just opposite the stirrup, in the inner ear, is. Fig. 113. The middle and inner ears, from a different view and on alarger scale than Fig. 111. a, the auditory canal of the outer ear; T, thetympanic membrane; m m, the middle ear; e, the Eustachian tube;I i, the inner ear, surrounded by boue; s, the stapes; I, the incus; M, themalleus. a fluid. Therefore the vibrations of the air at last cometo affect this fluid in the inner ear. A reference toFig. 113 will make this clear ; the sound enters theexternal-ear and passes down the auditory canal, A, andstrikes against the tympanic membrane, T, throwingit into vibrations ; these vibrations are communicated tothe handle of the hammer, M ; thence to the anvil, I ;thence to the stirrup, S ; and thence to the membrane towhich the stirrup is attached. As this membrane vi-brates it throws a fluid beyond it into correspondingvibrations; and these so affect the endings of the audi-tor v nerve that we have at last the sensation of hearing. 320 THE ESSENTIALS OF HEALTH. The Eustachian Tube. The mid
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectphysiology, bookyear1
