(单词翻译:单击)
Hi, guys! I just got back from a really fun hike in the woods.
嗨，伙计们！我刚结束树林里的有趣旅行。
I saw a lot of cool things, like wallflowers, and lots of birds, and pretty rocks.
我看到了许多有趣的事物，如桂竹香、大量的鸟和漂亮的石头。
But I only brought one thing back with me: lots of mosquito bites.
但我只带了一样东西回来，那就是许多的蚊虫叮咬。
Depending on where you live and what time of year it is,
根据你住的地方和季节，
if you've spent time outside, you've probably been bitten by mosquitoes too.
如果你在外面待过，你也可能会被蚊子咬伤。
Long after the mosquito is gone, you're left with red, itchy bumps, and I mean itchy.
蚊子离开很久以后，你身上留下了发痒的鼓包红肿，而我强调的是痒。
So what's going on? Why are mosquito bites so itchy?
那么发生了什么？为什么蚊虫叮咬这么痒？
To answer that question, we need to take a closer look at where these bumps come from.
为了回答这个问题，我们需要近距离观察鼓包从哪里来。
First, let's learn a little bit about the mosquito.
首先，我们先对蚊子做一点儿了解。
For one thing, only female mosquitoes bite.
一方面，只有雌蚊子咬人。
And for another thing, what we call a bite isn't really a bite at all;
另一方面，我们所称的咬根本不是真正的叮咬。
it's more like a jab from a thing called a proboscis.
它更像是来自于吻的刺伤。
Proboscis. Proboscis! It's such a fun word to say!
吻。吻！它是一个多么有趣的词！
A proboscis is a special mouthpart that some insects have.
吻是某些昆虫的一种特殊口器。
It looks kind of like a long tube or a straw.
它有点儿像长试管或吸管。
If you've ever had the chance to get a close look at a butterfly,
如果你曾有机会近距离观察蝴蝶的话，
maybe you've seen their long, curly proboscis,
或许你看到了它们卷曲的长吻，
which they use as a long tube to sip nectar from flowers.
它们把吻用作长管从花里啜取花蜜。
But the female mosquito?
但雌蚊子是怎么做的呢？
She uses her proboscis to take a tiny sip of blood from the blood vessels right beneath your skin.
它们利用吻从你皮肤下的血管里吸取少量的血液。
Her body makes special chemicals to help her do the job.
它的身体能产生特殊的化学物质帮它完成这份工作。
Some of them make your blood easier for her to drink.
有些物质能帮助它更轻易地吸血。
Others even help you from feeling the little pinch when her proboscis pokes you.
在它的吻刺你时，其他物质让你感觉不到一点儿夹痛。
After she's had her sip and she buzzes off, she leaves a little bit of those chemicals behind in your skin.
它在吸完匆忙离去之后，留下了一点儿化学物质在你的皮肤里。
And they set off signals in your body's immune system.
它们向你身体的免疫系统发送了信号。
Your immune system's job is to protect your body from invaders,
免疫系统的工作是保护身体免受外来者的侵害，
not ones from outer space but invaders like bacteria and viruses, any particles that can make you sick.
这里的外来者不是指来自外太空的入侵者，而是细菌病毒、或任何致病分子。
Kind of like soldiers protecting a fort,
免疫系统有点儿像保护城堡的士兵，
your immune system attacks just about anything that it doesn't recognize.
它会攻击任何不被识别的物质，
And that includes the chemicals left behind by the mosquito.
其中包括蚊子留下的化学物质。
Once your body discovers it's been bitten by a mosquito,
一旦身体发现它被蚊子咬了，
it sends some extra blood and other fluids to the bite.
就会运送更多的血液和其它液体到叮咬处。
This does a nice job of protecting the area so it can heal
它在保护伤口方面做得很好，所以能治愈伤口，
and helps your body get rid of the chemicals that the mosquito left behind.
也能帮助你清除蚊子留下的化学物质。
But it also makes the area around the bite swell up, causing a bump.
但它也使叮咬周围的区域肿了起来，形成了鼓包。
And that swelling sets off nerves in your skin around the bump.
鼓包会刺激它周围皮肤里的神经。
Nerves carry messages between parts of your body.
而神经在身体各部分之间传递信息。
So when you feel the tingly itch of a mosquito bite, that's the work of your nerves telling your brain,
所以当你感到蚊虫叮咬处发痒时，就意味着神经告诉了你的大脑，
"in case you haven't noticed, there's something going on down here."
“提醒你一下，这儿不太正常。”
And even though it's really hard, you shouldn't scratch those bumps;
不要挠这些鼓包，即使它很痒。
it's not good for you skin, and it actually makes everything worse.
这对你的皮肤不好，会让事情变得更糟。
Scratching irritates your skin even more.
挠它会让你的皮肤更恼怒。
And when that happens, your body's immune system tries even harder to stop whatever is bothering it.
那时，你的免疫系统会更努力地尝试消灭任何烦扰它的东西。
So that makes the bump even itchier.
所以这会使鼓包更痒。
Experts say that using ice or a paste made from baking soda and water on a mosquito bite
专家说用小苏打和水制成的冰块或糊状物放到鼓包处，
can actually help with the swelling and the itch.
会帮助消肿和止痒。
So remember: Stop scratching. Whatever it takes.
所以记住：不要挠鼓包。要不惜代价做到。
Thanks for joining us on SciShow Kids.
感谢您收看本期的儿童科学秀。
Do you have a question about bugs, birds, dinosaurs, or anything else?
你对虫子、小鸟、恐龙或其他东西有什么疑问吗？
Ask an adult to help you leave a comment below or e-mail us to kids@thescishow.com
找个大人帮忙在下方留言，或发邮件至kids@thescishow.com。
And we'll see you next time.
我们下期见！
