日批在线视频_内射毛片内射国产夫妻_亚洲三级小视频_在线观看亚洲大片短视频_女性向h片资源在线观看_亚洲最大网

首 頁 | 新聞英語 | 視聽英語 | 翻譯園地 | 實用英語 | 專欄作家 | 奧運英語 | 新詞新譯 | 書友天地 | 輕松英語  | 凈臉聯盟 | 英語論壇 | 少兒英語
您現在的位置: En_language tips > 輕松英語 > 一問到底 Dec 26, 2005
 





  Do you know how our fingernails grow?

Fingernails  
Do you know how our fingernails grow? Notes:
Fingernails and toenails grow from a point near the roots below the skin, at the base of the nail where the nail is very thin. White in color, and half-moon in shape, this semi-circle is appropriately named the "lunula, " and comprises a group of cells that manufacture keratin, a dead, hoof-like protein. The keratin like protein produced, gathers and merges with the nail plate, the dead armor that protects the soft and tender nail bed underneath, and pushes the entire nail up and out. Though the fingernails and toenails grow an average of two inches per year, their growth slows with age, and the average adult's fingernails grow only one inch over the course of eight months.

The base of the fingernails and toenails, as well as some of the nail along both sides of the nail, are embedded into the skin. Unlike other skin, this skin contains elastic fibers that connect it to the fingernail or toenail, and hold it firmly in place. The cuticle , a rim of skin over the lunula, protects it from bacterial infection, serves as a shock absorber, and shields the nail from any sudden impacts.

Though many consider dressing the fingernails up to go out a statement of beauty, or one of vanity, they serve those in the medical field as a diagnostic tool. Normally, the lunula, or half-moon, is white in color, indicating proper nutrition and good overall health. Blue lunula raise red flags that circulatory problems to the fingers may exist. Nails that are hard, brittle, and tend to split easily, may also be clues to poor circulation, infection, or disturbances of the glandularand nutritional systems.


Further nails that curl sharply around the finger point to coronary , liver, or lung diseases. Nails that are sunken in appearance often indicate anemia, a condition where an insufficient amount of oxygen is carried by the blood.

 

 


指甲下端的白色弧影,甲弧影

角蛋白,角質

 

 

 

 

 



角質層

 

 

 

硬而脆的

腺的




冠狀動脈
貧血癥

 
 
 
Copyright by chinadaily.com.cn. All rights reserved
版權聲明:未經中國日報網站許可,任何人不得復制本欄目內容。如需轉載請與本網站聯系。
None of this material may be used for any commercial or public use. Reproduction in whole or in part without permission is prohibited.
主站蜘蛛池模板: wwwxxx日韩| 亚洲男人的天堂av | 九九热在线观看视频 | 日韩美女一区二区三区 | 国产一区二区三区视频在线 | 在线色网站 | 黄色片aa| 人人草超碰 | 91在线观看免费高清 | 操在线视频 | 国产第5页 | 亚洲精品日韩丝袜精品 | 九九热精品视频在线播放 | 91最新在线视频 | 精品热久久| 国产成人精品一区二三区 | 成人国产免费视频 | 午夜视频a | 在线观看a视频 | 国产精品久久久久免费 | 在线观看视频福利 | 日韩一区二区三区在线播放 | 中文字幕亚洲欧美 | 青青草原在线免费观看视频 | 欧美第二区| 99视频在线观看免费 | 午夜影院一区二区 | 日韩中文字幕网站 | 一级黄色免费网站 | 欧美亚洲大片 | 亚洲天堂欧美 | 亚洲久草视频 | 操碰91| 午夜国产精品视频 | 狠狠操图片 | 91在线无精精品一区二区 | 91精品国产免费 | 在线免费中文字幕 | 日韩在线视频网站 | 一级黄色片a | 成人免费视频网站入口 |