The Anatomy and physiology of the organ of hearing : with remarks on congenital deafness, the diseases of the ear, some imperfections of the organ of speech, and the proper treatment of these several affections / By David Tod.

  • Tod, David.
Date:
1832
Catalogue details

Licence: Public Domain Mark

Credit: The Anatomy and physiology of the organ of hearing : with remarks on congenital deafness, the diseases of the ear, some imperfections of the organ of speech, and the proper treatment of these several affections / By David Tod. Source: Wellcome Collection.

Provider: This material has been provided by The University of Leeds Library. The original may be consulted at The University of Leeds Library.

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    SO as to cause that portion of the Membrana Tympani which is posterior to the Manubrium to be less, and the other portion anterior to it to be more concave than usual; and at the same time to cause the anterior half of the base of the Stapes to make a greater pressure on the membrane of the Fenestra Ovalis than its posterior half. When we press the body of the Incus downwards and forwards, we force its Long Process and the Stapes, and also the Manubrium Mallei, directly backwards, and pro- duce in the Membrana Tympani and Fenestra Ovalis actions the reverse of those stated in the preceding section, i When we press the body of the Incus directly down- wards, we force the Manubrium Mallei inwards, and at Ithe same time cause the inferior or straight margin of the base of the Stapes to produce a greater degree of pressure upon the membrane of the Fenestra Ovalis than its other Iportion. And when we press the Incus from the extre- Imity of its Long Process directly upwards, we cause the 'Semicircular margin of the base of the Stapes to make the greater pressure upon the membrane of the Foramen Ovale. We also observe in every motion which the Ossicula Auditus make, or are capable of making, that the Chorda Tympani is moved along with them. All these motions which we have described, and have produced by violence, are performed by the muscles of the Ossicula Auditus. For when we draw in the natural direction of the Anterior Mallei forwards, and in that of the Posterior Mallei backwards, at one and the same time, we force the Manubrium Mallei and its Processus Brevis directly outwards, and the remaining bones follow. When the Internus Manubrii Mallei contracts, which it does in- wards, the Manubrium follows it, and the motions of the Incus and Stapes take the same course. The Anterior Capitis Mallei draws the head of the Mal- leus forwards. The Superior draws it upwards and out- wards. The Obliquus Incudis Externus Posterior draws the Incus and head of the Stapes obliquely upwards and backwards. The Triangularis Incudis draws the Proces-