Gas composition in the middle ear cavity

本文用质谱法对鼓膜穿孔患者和正常人中耳腔气体成分进行了分析，结果表明：正常人中耳腔气体成分为：氮气83.7%、氧气9.2%、二氧化碳83.7%、二氧化碳9.2%。6.2%（各种气体的分压表示为713 mmHg的百分比）由于大气气体扩散到鼓膜穿孔的中耳腔中，预期鼓膜穿孔的中耳腔中的氧分压高于正常状态。中耳腔。在大气压环境下，中耳中的气压维持在1 ATA的机制取决于中耳腔粘膜中产生的气体的代谢。中耳中的气体代谢在声音传导中也起重要作用。此外，中耳腔中的低氧气分压导致微需氧细菌空气条件。中耳中的微需氧空气空间作为抵抗细菌感染的生理屏障。

The gas composition in the middle ear cavity in patients with perforated tympanic membrane and in normal subjects was analyzed by mass spectrometry.Results revealed that the middle ear gas composition in normal subjexts was ; nitrogen ; 83.7% , oxygen ; 9.2% , and CO_2 ; 6.2% (The partial pressure of the various gases was expressed as a percentage of 713 mmHg).The partial pressure of oxygen in the middle ear cavity with perforated tympanic membrane is expected to be higher than in the normal state because of diffusion of atmospheric gas into the middle ear cavity.The mechanism by which the gaseous pressure in the middle ear is maintained at 1 ATA under an environment of atmospheric pressure is dependent on the metabolism of the gases that are produced in the mucous membranes of the middle ear cavity.Gas metabolism in the middle ear also plays an important role in sound conduction. In addition, the low partial pressure of oxygen in the middle ear cavity results in a micro-aerophilic bacterium air condition.The microaerophilic air space in the middle ear acts as a physiological barrier against bacterial infection.