A text-book of the diseases of the ear for students and practitioners / by Adam Politzer ; tr. at the personal request of the author and ed. by Milton J. Ballin and Clarence L. Heller.

  • Politzer, Adam, 1835-1920.
Date:
1903
Catalogue details

Licence: Public Domain Mark

Credit: A text-book of the diseases of the ear for students and practitioners / by Adam Politzer ; tr. at the personal request of the author and ed. by Milton J. Ballin and Clarence L. Heller. Source: Wellcome Collection.

Provider: This material has been provided by the Francis A. Countway Library of Medicine, through the Medical Heritage Library. The original may be consulted at the Francis A. Countway Library of Medicine, Harvard Medical School.

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    even during quiet respiration ; in other cases, however, an act of deglutition or a powerful expiration with open or closed nostrils is necessary to make the tube permeable.* 2. The Eustachian tube is opened during the act of swallow- ing, chiefly by the action of its muscles, especially by the abductor tubae, t as is- shown by the experiments of Toynbee and the author. I 3. A difference of pressure is more easily equalized when the interchange of air takes place from the tympanum to the pharynx, than from the latter to the former. Hamnierschlag (Wien. med. Woch., 1896, No. 39), having observed regular pulsation and respiratory movements on the drum in man by means of a special microscopic contrivance, came to the conclusion that the normal Eustachian tube is continually open during respiration. Kreidl (Sitzungen d. physiol. Clubs. Wien., 1899), on the other hand, found, through experi- ments on dogs, that the tube is closed when at rest. When illuminating gas was introduced under moderate pressure into the auditory canal of a dog after the drum had been perforated, the gas could be lighted at the ostium pharyngeum only when the tube was opened by electrical irritation of its muscles. Application of the Foregoing to the Pathology of the Ear. From the above-mentioned physiological facts, we gather the following considerations in reference to the pathology of the ear : 1. The permeability of the Eustachian tube is of great impor- tance for the function of hearing. If the tube becomes imper- meable through swelling of its mucous membrane, or through accumulation of secretion, conditions will shortly arise which indicate an interruption between the air in the tympanic cavity and the external atmosphere. When the air is confined in the tympanic cavity, congestion and exudation are brought about by this rarefaction, and as the atmospheric pressure predominates, the membrana tympani and the ossicular chain are tensely forced inwards, whereby their power of vibration is diminished. 2. Through the opening of the Eustachian tube which takes place during the act of swallowing, the resistance which opposes the current of air from the pharynx to the tympanic cavity is * Confirmed by Mach and Kessel: Die Function der Trommelhohle und der Tuba Eustachii. Wien. Acad. Sitzungsberichte, 1872. f By means of experiments on vivisected dogs, the author was able to observe a widening of the fissure of the tube in the lateral pharyngeal wall by irritation of the trigeminus in the cranial cavity. The dissection showed that the widening was caused by the tensor palati muscle. (' Ueber eine Bezie- hung des Trigeminus zur Eust. Ohrtrompete,' Wilrzburger naturw. Zeitschr., 1861. J Diseases of the Ear, 1880.