「Nerve06/eyes and ears/pharyngotympanic (Eustachian) tube」の版間の差分

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The pharyngotympanic (Eustachian) tube is connected to the pharynx and is usually closed, making the tympanic cavity a closed space.  During swallowing or yawning, the tube is opened and the cavity becomes open to the outside, making the pressure inside the cavity equal to that of the atmosphere.   
The pharyngotympanic (Eustachian) tube is connected to the pharynx and is usually closed, making the tympanic cavity a closed space.  During swallowing or yawning, the tube is opened and the cavity becomes open to the outside, making the pressure inside the cavity equal to that of the atmosphere.   


[[ファイル:01305.jpg|400px|left]] At the first floor of a building, the pressure of the cavity is equal to the atmospheric pressure at that level (shown in thick blue).  Both the tube and cavity are closed.
[[ファイル:01305en.jpg|400px|left]] At the first floor of a building, the pressure of the cavity is equal to the atmospheric pressure at that level (shown in dark blue).  Both the tube and cavity are closed.
 
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[[ファイル:01306.jpg|400px|left]] 航空機や高層ビルのエレベータに乗ると高度が上昇し、外気圧が低下する(薄い青色)。鼓室は閉じた空間であるので、内圧は変化しない(濃い青色)。その結果、鼓膜の内外で圧力差が生じ、鼓膜は湾曲する。鼓膜自体にも知覚神経があるため、この湾曲は異和感ないし痛みとして感覚される。
[[ファイル:01306en.jpg|400px|left]] The atmospheric pressure is lowered (shown in light blue) as an airplane or an elevator of a high building goes up.  Since the tympanic cavity is a closed space, the pressure inside does not change from the 1st floor level (shown in dark blue).  This results in pressure difference on the two sides of the tympanic membrane, which becomes curved. Since the tympanic membrane also has sensory nerves, the curve causes an uncomfortable or painful sensation making the subject want to 'pop' his ears.
 
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[[ファイル:01307en.jpg|400px|left]] At this time, swallowing would cause the tube to open, releasing the high pressure to the pharynx.
 
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[[ファイル:01307.jpg|400px|left]] このとき、意識的に嚥下を行なうと耳管が開き、鼓室内の高い圧力は咽頭に抜ける。
[[ファイル:01308.jpg|400px|left]] This cancels the pressure difference on the two sides, and the curving, of the tympanic membrane.  The ears are 'popped', and the uncomfortable sensation disappears.
 
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[[ファイル:01308.jpg|400px|left]] これにより鼓膜内外の圧力差がなくなる。鼓膜も平坦になる。耳の異和感も同時に消失することは、日常しばしば経験する。
 


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<GIFT>
<GIFT>
//LEVEL:2
//LEVEL:2
//RAND
//RAND
耳管は嚥下時に  {=開く.~閉じる}
The pharyngotympanic (Eustachian) tube is {=opened~closed} during swallowing. 
 
 
</GIFT>
</GIFT>

2015年4月24日 (金) 22:33時点における最新版

The pharyngotympanic (Eustachian) tube is connected to the pharynx and is usually closed, making the tympanic cavity a closed space. During swallowing or yawning, the tube is opened and the cavity becomes open to the outside, making the pressure inside the cavity equal to that of the atmosphere.

01305en.jpg

At the first floor of a building, the pressure of the cavity is equal to the atmospheric pressure at that level (shown in dark blue). Both the tube and cavity are closed.


01306en.jpg

The atmospheric pressure is lowered (shown in light blue) as an airplane or an elevator of a high building goes up. Since the tympanic cavity is a closed space, the pressure inside does not change from the 1st floor level (shown in dark blue). This results in pressure difference on the two sides of the tympanic membrane, which becomes curved. Since the tympanic membrane also has sensory nerves, the curve causes an uncomfortable or painful sensation making the subject want to 'pop' his ears.


01307en.jpg

At this time, swallowing would cause the tube to open, releasing the high pressure to the pharynx.


01308.jpg

This cancels the pressure difference on the two sides, and the curving, of the tympanic membrane. The ears are 'popped', and the uncomfortable sensation disappears.


Challenge Quiz

1.

The pharyngotympanic (Eustachian) tube is opened closed during swallowing.