| Budget Amount *help |
¥3,400,000 (Direct Cost: ¥3,400,000)
Fiscal Year 1990: ¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 1989: ¥2,600,000 (Direct Cost: ¥2,600,000)
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| Research Abstract |
The organs of the Otorhinolaryngology are cavity organs, and their internal surfaces are lined with a layer of the mucous membrane. The these cavity organs is filled gas tension of the peculiar components. Hence, in such a structure, when it is exposed to the environment of hyper and hypo baric pressure, this gas component also tends to change, affected by the environmental pressure. In such pressure adjustment, since a cavity organ itself has no pumping function, the pressure is brought in equilibrium with the environmental pressure as the results of the application of Boyle's low. This signifies that the atmosphere always comes in and out of cavity organs due to treathing. It has been provided, however, that peculiar mucous respiration is made in cavity and peculiar gas tension exist in each cavities. Adove all, the respiration by the mucous membrane of the middle ear cavity is significantly important. This respiration all the time yields gas in a cavity. And this is the physiologica
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l function to release gas tension on the outside of a middle ear cavity through the auditory tubes, when the partial pressure of gas tension becomes higher than the atmospheric pressure. This function serves to provide the gas layer of 1 ATA all the time at the tympanic side so that a tympanic membrane may efficiently vibration, responding to the vibration of a sound. In other words, this physiological function denies the explanation formerly described in a text book, that gas is supplemented from an auditory tube to the middle ear cavity.
This physiological function can be explained by the fact that the oxygen tension pressure in the middle ear cavity is about 1/3 (approximately 50mm Hg) of the atmosphere, and that mastoid cells have a volume 20 time as longe as a tympanic cavity and the surface area of the mucous membrane is about 40 cm^2. Furthermore, when the mucous membrane structure is studied, such a fact is learned as a submucous capillary contacts gas through only one cell membrane. This fact suggests the existence of gas metabolism in an middle ear cavity, although it is not a respiratory function which completely exchanges gases as in a lung. In addition, when a person lies in a lateral position, a difference is observed in the extent of opening of an auditory tube between the upper and down side auditory tube. At this time, the internal pressure in the under side middle era cavity indicates a higher value with a significance than the upper side. This is a phenomenon in which the opening and closing function of the under side auditory tube becomes not always to open at every swallowing movement. This phenomenon implies that an auditory tube organically adjusts the opening and closing function corresponding to the change in the physiological environment of an middle ear cavity. This phenomenon, showing the appearance of the difference in the upper and under side of an auditory tube, denies the former view that the ventilation in the middle ear cavity is defense mechanism of the auditory tube. The reason is because of the fact that the changes in the physiological internal environment, in the anatomical relative position, etc. of the middle ear cavity affect the function of an auditory tube. In other words, the organic relation of complete natural dependence is formed between the function of an auditory tube and the ventilation in the middle ear cavity. As stated above, it has been corroborated that the mucous membrane respirating function in the middle ear cavity plays an important role in the physiology of the ventilation in the middle ear cavity under the atmospheric pressure. Less
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