時差N小時:梅子干皮膚 Prune Skin

Prune skin on this Moment of Science At some time,we've all probably taken a long bath or been in thepool for a while, and then notice that parts of thepalms of our hands and the bottoms of our feetbecame wrinkled. This Moment of Science answerstwo questions about this. Why does it happen? Andwhy doesn't our whole body wrinkle like that?

梅子干皮膚?對，我們這次的內(nèi)容與皮膚有關(guān)。有時候，我們可能在浴池或泳池中的時間較長，然后，會發(fā)現(xiàn)手掌和腳底板的皮膚起了褶皺。本次內(nèi)容將對這一現(xiàn)象做出科學(xué)的解釋。為什么會發(fā)生這種情況?為什么我們的整個身體不會出現(xiàn)褶皺? The answer lies in the structure of our skin, and that is not the same allover. The outer layer of skin, the epidermis, on our palms and the soles of our feet is thickerthan the skin on the rest of our body. When we soak in water, the epidermis all over our bodyabsorb some water and swells. Because the skin on our palms and soles is thicker, it canabsorb more water, and therefore, swells more.

答案在于，我們身體各處的皮膚結(jié)構(gòu)并非完全相同。手掌或足底的外層皮膚(真皮)要比身體其它部位的皮膚較厚一點(diǎn)。當(dāng)浸泡在水中時，外層皮膚會吸收一些水，然后膨脹。因為手掌和足底的皮膚較厚，它吸收的水分更多，因此膨脹得也就越多。

That seems simple enough. But why did ends our fingers and toes wrinkle like black prunesand not the rest of us? Most of our skins absorbs water and swells rather evenly, but there issomething different about ends of our toes and fingers -- there is a nail on one side. The ends ofthe fingers and toes can't swell towards the nails, so the skin bunches up opposite nails on thepalm side of our fingers and the sole side of our toes. This bunching up of the skin gives us thewrinkles, prune skin.

道理似乎很簡單了。但是，為什么手指和腳趾的末端褶皺得像黑色的梅子干，但其它部位則不會如此呢?原因在于，當(dāng)皮膚吸收水分時，大部分會均勻地膨脹，但手指和腳趾的末端結(jié)構(gòu)有點(diǎn)特殊：那里生長著指甲(趾甲)。當(dāng)吸收水分時，手指和腳趾末端的皮膚無法向指甲(趾甲)的方向膨脹，因此，那兒皮膚就會縮成一團(tuán)。結(jié)果，我們看到，指甲(趾甲位置的皮膚會皺起來，看起來就像梅子干一樣。

1. wrinkle n. 皺紋 v.(使)起皺紋

例句：He wrinkled up his forehead in perplexity. 他困惑地皺起了眉頭。

She's beginning to get wrinkles round her eyes. 她的眼角開始有皺紋了。

2. absorb vt. 吸收

例句：Plants can absorb carbon dioxide and releaseoxygen. 植物可以吸收二氧化碳釋放氧氣。

3. swell vi. 腫(膨)脹，鼓起

例句：The murmur swelled into a roar.

竊竊私語的聲音變大形成一片喧嘩。

4. bunch up 縮成一團(tuán)

When muscle tissue shortens, it also bunches up. 肌肉在收縮的同時,也會聚成團(tuán)。