日韩精品久久一区二区三区_亚洲色图p_亚洲综合在线最大成人_国产中出在线观看_日韩免费_亚洲综合在线一区

您現在的位置: > Language Tips > Easy English > Odd Question  
 





  Why do we get Goose Bumps when it is cold?
[ 2006-03-29 09:13 ]


Goose bumps are a vestige from the days when humans were covered with hair.

When it's hot and you need to cool down, little muscles at the base of each hair relax. Your hair becomes relaxed. Your sweat glands pump out body heat in sweat. Your blood vessels get big to take more heat to the skin to get rid of it. When it's cold, the arrector muscle pulls the hair up. The duct to the sweat glands gets small to conserve heat. Our blood vessels also get small to save heat.

Hair standing up doesn't make very good insulation we don't have enough fur for that. Humans don't have very much hair on their bodies anymore. Millions of years ago, humans probably did. And that hair standing on end helped keep people warmer. Those little muscles we have on the end of each hair still work. They still make goose bumps.

Cold is not the only thing that can cause our hair to stand on end. Fear or anger can cause the same reflex. The same is true for other mammals. You'll notice that on a cat or dog. Their fur gets bigger when they're angry or afraid.

vestige: 殘余,痕跡

 

 

gland:腺

 

muscle:立毛肌

conserve:貯藏



insulation:隔熱

 

 


reflex:反應

 
 
 




主站蜘蛛池模板: 激情五月婷婷综合网 | 91免费在线| 精品久久中文久久久 | 国产欧美性综合视频性刺激 | 综合第一页 | 国产在线视频2019最新视频 | 小宝与康熙粤语 | 一级毛片视频 | 欧美电影一区 | 国产在线观看福利片 | 99久久99| 激情小说五月 | 久久久久国产成人精品亚洲午夜 | 亚洲欧美日韩精品久久奇米色影视 | 国产亚洲精品久久久久久久久动漫 | 日本免费一区二区三区视频 | 九二淫黄大片看片 | 小明免费视频一区二区 | 91国在线产 | 国产农村妇女毛片精品久久麻豆 | 天天舔| 一区二区三区在线看 | 2021精品国产综合久久 | 奇米影视图片 | 一区二区三区回区在观看免费视频 | 免费a级在线观看播放 | 久久精品一区二区三区不卡牛牛 | 成人国产精品免费观看视频 | 一区二区三区欧美在线观看 | 黄色片视频在线观看 | 中文字幕亚洲精品 | 成人av一区二区三区 | 艹艹艹逼| 亚洲最新在线 | 91精品国产91久久久久久最新 | 九九热视频在线观看 | 国产精品色综合久久 | 天天干天天操天天爽 | 亚洲国产99在线精品一区二区 | 99青青青精品视频在线 | 久色乳综合思思在线视频 |