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皮肤上的茧是如何形成的?

所属:听力板块 来源:普特英语听力 阅读:7137 次 评论:0 条 [我要评论]  [+我要收藏]

小编摘要:人体皮肤由于劳动过程长期摩擦造成皮肤表皮细胞坏死而形成的,主要出现于手掌、足掌等部位。长时间的受到磨檫,组织细胞的老死,角质层的严重受损形成手茧.

皮肤上的茧是如何形成的?



Most of us are familiar with calluses.

These extra-tough patches of skin aregenerally quite useful–we might even say handy–because they actlike a kind of natural armor, protecting areas of skin that get an unusualamount of wear and tear. Have you ever wondered exactly what a callus is, orhow it forms on your skin?

Callus formation is triggered by pressureor abrasion. The heel of your foot as it rubs inside your shoe, or the palm ofyour hand if you’re doing a lot of manual labor are good examples of this.

While it might feel like a callus issomething extra, added to your skin, it’s actually just abuild-up of what’s already there.

Here’s How It Works

Your skin has a number of layers ofdifferent types of cells.

The outermost is a layer of hardened, deadcells. This top layer is usually about twenty-five cells thick, and itconstantly replaces itself as the outermost cells flake off to be replaced bynew hardened, dead cells underneath.

All About Friction

If your skin is subject to an unusualamount of friction, this layer of dead cells increases. New dead cells areadded faster than the old ones slough away. This can build up the outer layerfrom twenty-five cells thick to over a hundred cells thick. You’ve grown acallus.

While calluses are generally useful, if theprocess continues unchecked a callus can thicken into a cone-shaped structurecalled a corn. These super calluses can be quite painful, and may require theattention of a doctor.

译文

对于“老茧”,我们都很熟悉。

这些皮肤上突出的硬皮是很有用的,也可以说是方便,因为他们扮演着保护常磨损皮肤的天然盔甲的角色。你是否思考过什么是老茧?他又是怎样形成的?

老茧是由压力和摩擦而形成。脚后跟的茧是由其在鞋里摩擦而形成,正如手茧是在大量的劳动过程中形成。

尽管看起来似乎是皮肤上多出的部分,然而事实是已经存在的皮肤角质的累积。

形成过程

皮肤是由若干层不同类型的皮肤构成。

表层是一些坏死的硬细胞,通常有25个细胞那么厚,表层细胞不断的脱落,取而代之的是下层硬的坏死细胞,由此而完成自我更替过程。

一切皆由摩擦引起

假如皮肤受到不寻常量的摩擦,这层坏死细胞将会增加,新的坏死细胞增长速度比旧细胞脱落的速度快,这就致使皮肤表层的厚度增加到100个细胞那么厚,由此,老茧便形成。

虽然一般来讲,茧是有益的,但如不控制其过程,老茧厚度就会增加到被称作鸡眼的锥形结构,那样就会很疼,甚至需要去看医生。

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2011-08-27 16:20 编辑:pliny
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