<tt id="6hsgl"><pre id="6hsgl"><pre id="6hsgl"></pre></pre></tt>
          <nav id="6hsgl"><th id="6hsgl"></th></nav>
          国产免费网站看v片元遮挡,一亚洲一区二区中文字幕,波多野结衣一区二区免费视频,天天色综网,久久综合给合久久狠狠狠,男人的天堂av一二三区,午夜福利看片在线观看,亚洲中文字幕在线无码一区二区
          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: 四虎国产精品永久地址49| 精品久久久久久无码不卡| av天堂久久精品影音先锋 | 99r久视频精品视频在线| 亚洲欧美日韩人成在线播放| 亚洲产国偷v产偷v自拍色戒| 日本精选一区二区三区| 国产乱啊有帅gv小太正| 欧美成人精品 一区二区三区| 91色老久久精品偷偷性色| 国产18禁黄网站禁片免费视频 | 国产不卡在线一区二区| 熟妇激情一区二区三区| 免费观看a毛片一区二区不卡| 国产97人人超碰CAO蜜芽PROM| 亚洲an日韩专区在线| 国产成人女人在线观看| 久久精品人人槡人妻人人玩AV| 天天爽夜夜爽人人爽曰| 亚洲精品无码久久一线| 日本免费一区二区三区高清视频 | 国产乱人无码伦av在线a| 丰满无码人妻热妇无码区| 国产精品自拍视频入口| 久久午夜无码鲁丝片直播午夜精品 | 日本精品aⅴ一区二区三区| 国产国语对白露脸正在播放 | 中文国产成人精品久久不卡| 精品熟女少妇免费久久| 男女啪啪激烈无遮挡动态图| 欧美人禽zozo动人物杂交| 国产三级精品福利久久| 日韩欧美精品suv| 中文字幕乱码一区二区免费| 狠狠综合av一区二区| 深夜福利啪啪片| 亚洲一区二区三区av激情| 日本一区不卡高清更新二区| 国产地址二永久伊甸园| 成人国产精品一区二区免费麻豆 | 91亚洲国产三上悠亚在线播放|