發表者 learnang 開 2007-01-10 09:33:52
A belch is quite different from a hiccup. The directions of air flow are exactly opposite in these two conditions. Please check out the following info.A belch
is the expulsion
through the mouth of gas from the stomach or esophagus. This is accomplished by relaxing the esophageal sphincters (upper and/or lower) and increasing abdominal pressure.
is an extraordinary type of respiratory movement involving a sudden inspiration (intake of air)
due to an involuntary contraction of the diaphragm accompanied by closure of the glottis (the vocal apparatus of the larynx).
The abrupt inspiration is the result of a sudden contraction of the diaphragm. Closure of the glottis then halts the incoming air. The column of air strikes the closed glottis to produce the characteristic sound: a hiccup.
Hiccups are often rhythmic
. They are usually just a minor nuisance, but prolonged hiccups can become a major medical problem. (http://www.medterms.com/script/main/art.asp?articlekey=3754