免费日韩片_欧美成人精品一区二区男人小说_国产乱码一区二区三区四区_国产精品国产三级国产aⅴ入口_成人看的污污超级黄网站免费_欧美一级在线免费观看_成人午夜免费无码福利片_国产乱人伦偷精品视频色欲_aaa少妇高潮大片免费看_国产精品1234_亚洲精品国产suv一区88_中文字字幕在线中文无码_精品亚洲区_午夜九九九_国产av国片精品jk制服丝袜_色综合亚洲_亚洲成av人片无码bt种子下载_欧美色就色_精品少妇的一区二区三区四区_男人用嘴添女人下身免费视频

 

流感病毒侵入體內(nèi)，發(fā)燒一般都不可避免。為什么一感染這樣的病毒體溫就要升高呢？發(fā)燒到底對人體有什么樣的影響呢？

When your body temperature rises because of an infection, it's called a fever. Fevers are caused by chemicals called pyrogens (熱源) lowing in the bloodstream. Pyrogens make their way to the hypothalamus (視丘下部) in the brain, which is in charge of regulating body temperature. When pyrogens bind to certain receptors in the hypothalamus, body temperature rises.

One common pyrogen is called Interleukin-1 (IL-1, 白細(xì)胞間介素). IL-1 is produced by white blood cells called macrophages（巨噬細(xì)胞）when they come into contact with certain bacteria and viruses. IL-1 has multiple purposes, one of which is to signal other white blood cells, called helper T cells, into action.

One purpose of a fever is thought to be to raise the body's temperature enough to kill off certain bacteria and viruses sensitive to temperature changes. One interesting debate right now, therefore, is, "Should you lower a fever?" Aspirin, for example, will reduce fever; but if the fever is actually helping rid the body of infection, then lowering it might not be a good idea. On the other hand, people sometimes die from fever. Right now the general medical consensus falls on the "reduce the fever" side of the fence. 

（來源：howstuffworks.com 英語點津 Helen 編輯）

我要了解更多趣味百科知識