送交者: Latino2 于 2005-8-16, 09:29:17:
打呼的原因不是鼻子堵塞，而是喉咙太窄，越窄呼声越大。
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How some people are born snorers
Scientists have discovered why it is that some people are chronic snorers. By carrying out head and neck scans of snorers and non-snorers, the Slovenia team found it was down to the shape of the throat.
Snorers have narrower throats and the smaller the opening is, the loader the snore. Contrary to popular opinion, nasal blockages do not cause snoring though they may "amplify the loudness", the researchers told Chest journal. Dr Igor Fajdiga and his team studied 40 volunteers - 14 were non-snorers, 13 were moderately loud snorers and 13 were loud snorers, according to their spouses.
How loudly people snored was directly related to the extent that their throat narrowed when they inhaled during their sleep - the narrower the throat, the bigger the snore. A culprit was the soft palate, which is the soft tissue at the back of the roof of the mouth. The snorers' soft palates were much bigger than those of non-snorers, meaning it blocked smooth airflow. Turbulent airflow is what creates the noise.
When we are awake we have enough muscle tone to keep the airways open. However, when we are asleep we lose this tone. Being older and overweight can make the problem worse. (C)BBC