Remember the time you fell off your bike or bumped your head on a sharp corner?
还记得你从自行车上摔下或一头撞到尖角之时吗？
Childhood injuries are things we'd often like to forget,
我们经常选择忘记童年时受的伤，
but our bodies often carry the memories in the form of scars.
但是在我们身体上留下的伤疤依然带着这段回忆。
So what are these unwanted souvenirs and why do we keep them for so long after that unintended vacation to the emergency room?
但是这些本想要的“纪念品”到底是什么呢，我们又为何在一次不情愿的医院之旅后，将它们留下呢？
The most common place we see scars are on our skin,
最常见的伤疤位置是在我们的皮肤上，
a patch that looks slightly different from the normal skin around it.
是一块与看起来正常皮肤不一样的皮肤。
Often, this is considered an unfortunate disfigurement,
这经常被认为是一个不幸的“毁容”，
while other times, deliberate scarification has been used in both traditional and modern cultures,
但有些伤疤是故意为之的，在传统和现代文化中都有这种现象，
to mark a rite of passage or simply for aesthetic decoration.
有时是纪念一个仪式，其他则是简单的装饰。
But the difference isn't only cosmetic.
但是伤疤拥有的不仅仅是外形上的区别。
When we look at healthy skin tissue under a microscope,
当我们在显微镜下观察健康的肌肤组织时，
we see the cells that perform various functions connected by an extracellular matrix, or ECM.
我们可以看见各种细胞起到不同的作用被ECM（细胞外基质）所连接。
This is composed of structural proteins, like collagen, secreted by specialized fibroblast cells.
ECM由结构蛋白所组成，像是胶原蛋白，由成纤维细胞分泌。
Well-arranged ECM allows for transportation of nutrients, cell-to-cell communication, and cell adhesion.
紧密排列的ECM让营养物质得到传输，促成细胞之间的交流和细胞黏附。
But when a deep wound occurs, this arrangement is disrupted.
但是当产生一个很深的伤口时，这种排序被打乱。
During the process of wound healing, collagen is redeposited at the wound site,
在愈合的过程中，胶原蛋白会在伤口旁重新沉淀，
but instead of the basket-weave formation found in healthy tissue,
但是不同于在健康组织中的篮织形成法，
the new ECM is aligned in a single direction, impeding inter-cell processes, and reducing durability and elasticity.
新的ECM以单向排列，这阻止了细胞间的联系，并且减少了耐久性和伸展性。

To make matters worse, the healed tissue contains a higher proportion of ECM than before, reducing its overall function.
让情况变得更糟的是，痊愈后的组织拥有更多的ECM，反倒使它的功能不如从前。
In the skin, the overabundance of collagen interferes with its original functions,
在皮肤中，过量的胶原蛋白会妨碍它原本的作用，
like producing sweat, controlling body temperature and even growing hair.
比如说出汗、控制体温或是生长毛发。
The scar tissue is fragile, sensitive to changes in temperature and sensation,
伤疤组织是非常脆弱的，并且对于温度的变化十分敏感，
and should be kept in moist environments to maximize healing.
而且为了达到最好的愈合效果，必须放置在潮湿的环境下。
This presence of excessive fibrous connective tissue in an organ is known as fibrosis,
这种过量的纤维性结缔组织被称为纤维症，
and if that term sounds familiar, it's because our skin is not the only organ vulnerable to scarring.
如果这个词听起来十分耳熟的话，那是因为我们的皮肤并非唯一易有伤疤的器官。
Cystic fibrosis is a genetic disorder that causes scarring of the pancreas,
囊肿性纤维化是一种遗传疾病，会在胰腺上产生伤疤，
while pulmonary fibrosis is a scarring of the lungs, resulting in shortness of breath.
而肺纤维化则是在肺上产生伤疤，从而形成呼吸困难。
Scarring of the heart and the buildup of ECM following a heart attack can inhibit its beating, leading to further heart problems.
在心脏上结疤和产生ECM会导致心脏病，会阻止其跳动，并会产生更多的心脏问题。
What's common to all these conditions is that although it retains some of the original functions,
所有这些状态的共性是，虽然伤疤组织依然有剩余的一些原功能，
the scar tissue formed after a wound is inferior to the native tissue it replaces.
但是在受伤过后它总是不如健康的原始组织的。
However, there is hope.
但是，我们还是有希望的。
Medical researchers are now studying what causes fibroblast cells to secrete excessive amounts of collagen
医药工作者现在正在研究是什么促使成细胞组织分泌过量的胶原蛋白，
and how we can recruit the body's other cells in regenerating and repopulating the damaged tissue.
以及我们的身体是如何“召集”其他的体细胞来重新建造被损坏的组织。
By learning how to better control wound healing and the formation of scar tissue,
当我们学到如何更好地控制伤口，愈合受伤处的皮肤组织，
we can utilize the multi-billion-dollar budgets currently used to address the aftermath of wounding in a much more efficient manner,
我们就能更有效地利用目前用在研究伤口愈后处理的数十亿美元预算，
and help millions of people live better and healthier lives.
并帮助上百万人活得更好更健康。
But until then, at least some of our scars can help us remember to avoid the sorts of things that cause them.
但在那之前，我们的伤疤会帮助我们记得去避开那些产生伤疤的事情。