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: 国产免费福利视频一区二区 | 狠狠操网| 色淫湿视频 | 激情插插插 | 国内成人自拍视频 | 欧美一级黄色网 | 亚州人成网在线播放 | 日韩欧美不卡在线 | 毛片a在线 | 欧美电影网 在线电影 | 亚洲人性生活视频 | 精品在线视频一区 | 国产男女免费完整版视频 | 成人精品一区二区三区 | 一级aaaaaa片毛片在线播放 | 日韩激情视频在线 | 久久亚洲国产精品 | 久久久久久久久久爱 | 久久国产精品99久久久久久牛牛 | 亚洲精品免费在线 | 香港免费毛片 | 国产婷婷精品av在线 | 国产日韩亚洲不卡高清在线观看 | 免费一级网站 | 国内精品免费视频 | 九九精品视频一区在线 | 国产乱码精品一区二区三区中文 | 日韩毛片欧美一级a网站 | 亚洲精品成人 | 色综合亚洲天天综合网站 | 国产精品久久久久久吹潮 | 免费看欧美成人性色生活片 | 99草在线| 污污小视频在线观看 | 羞羞的视频在线免费观看 | 亚洲一区二区三 | 亚洲aaa视频| 国产一区二区精品尤物 | 欧美视频区 | 欧美精品一区在线 | 亚洲国产片高清在线观看 |