. A treatise on anatomy, physiology, and hygiene : designed for colleges, academies, and families. and by the chain of smallbones that are enclosed in this cavity. 967. The use of the Eustachian tube is to admit air intoihe tympanum, which renders the pressure on both sides equal,and thus its membrane is kept in a proper state of tension. 963—971. Give the physiology of the organs of hearing. 963. What ishearing ? Are the precise functions of the different parts of the ear known ?964. What is the function of the external ear ? 965. Of the membranatympani ? What observation in reference to this
. A treatise on anatomy, physiology, and hygiene : designed for colleges, academies, and families. and by the chain of smallbones that are enclosed in this cavity. 967. The use of the Eustachian tube is to admit air intoihe tympanum, which renders the pressure on both sides equal,and thus its membrane is kept in a proper state of tension. 963—971. Give the physiology of the organs of hearing. 963. What ishearing ? Are the precise functions of the different parts of the ear known ?964. What is the function of the external ear ? 965. Of the membranatympani ? What observation in reference to this membrane ? 966. What isthe supposed office of the middle ear ? 967. What is the use of the Eu-stachian tube ? PHYSIOLOGY OF THE ORGANS OF HEARING. 421 Observation. When near a cannon, or a field-piece, aboutbeing discharged, by opening the mouth the impression uponthe auditory nerve will be diminished, and the unpleasant sen-sation lessened. This is the result of the air in the middle earescaping through the Eustuchian tube, when the vibrations ofthe membrana tympani are violent. Fig. FiR 148. A view of all the parts of the ear. 1, The tube that leads to the .nternalear. \ The drum of the ear. 3, 4, 5, The bones of the ear. 7™e centra partof the labyrinth, (vestibule.) 8, 9, 10, The semicircular canals 11, 12, The^chan-nels of the cochlea. 13, The auditory nerve. 14, The channe. from the earto the throat, (Eustachian tube.) 968 But little is known of the functions of the internalear; its parts are filled with a watery fluid, in which the fila-ments of the auditory nerve terminate. What observation in this connection ? 963. What is the function of theinternal ear ? 36 422 ANATOMY, PHYSIOLOGY, AND HYGIENE. 969. Many of the parts just enumerated aid in hearing, butare not absolutely essential to this sense. But if the vestibuleand auditory nerve are diseased or destroyed, no sound is thenperceived. If this sense is destroyed in early life, the personalso loses th
Size: 1770px × 1412px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bo, booksubjectanatomy, booksubjecthygiene, booksubjectphysiology
