Whether it's the latest scary movie or some sparkly vampire book.

無論是最新的恐怖電影，或是一些閃耀的吸血鬼書籍。

Blood seems to be everywhere, well, hopefully not real blood because that would be gross.

血似乎無處不在，但希望不是真的血，因為那會很噁心。

However, one thing that's not mentioned in a lot of these stories is blood types.

但是有件事沒有被這些故事提及到，那就是血型。

What do all of these letters and plus signs mean anyway?

這些字母跟右上方的加號到底代表什麼呢？

Luckily, I'm here to help.

幸運的是，我來幫助大家了。

For most of human history, we thought that all blood was the same.

人類歷史中大部分的時間裡，我們都以為所有血都是一樣的。

In fact, it wasn't until the 20th century that we discovered that we were wrong.

事實上，一直到 20 世紀我們才發現我們錯了。

When foreign objects like bacteria or viruses get into our body, your white blood cells produce antibodies which are like your own personal army.

當像細菌或是病毒外來體進入我們的身體時，你的白血球就會製造抗體，就像你的私人軍隊一樣。

These antibodies recognize the foreign object, which we call an antigen and attack it.

這些抗體會認出外來體並攻擊它，而我們稱這些外來體為抗原。

The antibody then attaches itself to the antigen similar to a locking key, which is what keeps you from getting sick.

抗體接著就會把自己附著在抗原的上，像上鎖的鑰匙般，這就是為什麼你能免於生病的原因。

So there's no reason why any antigens should still be in your body, right?

所以抗原沒有任何理由會待在你的身體裡，對吧？

Well, wrong.

這個嘛，錯了。

Your red blood cells naturally contain millions of antigens that your immune system doesn't react to, and the antigens that you have in those red blood cells determine your blood type.

你的紅血球細胞天生就含有數百萬的抗原，而你的免疫系統不會對它們起反應，然後這些在你紅血球裡的抗原就決定了你的血型。

For example, if you have both A and B antigens, your blood type is AB.

舉例來說，假如你同時擁有 A 跟 B 的抗原，那你的血型就是 AB 型。

If you have neither A nor B antigens, then you are a type O.

如果你們沒有 A 也沒有 B 抗原，那你就是 O 型。

Additionally, if you have type A blood, then you have anti-B antibodies, this is why you have to be careful if you get a blood transfusion.

此外，如果你是 A 型血，還有 B 抗體的話，你在接受輸血的時候就一定要小心。

If you receive someone else's blood that's a type B, your immune system will attack that blood, thinking it's a foreign object.

如果你接受某人的 B 型血液，你的免疫系統會認為它是外來體，並攻擊對方的血液。

Lastly, if you hear the word "positive" at the end of your blood type, you have an additional antigen called the Rh factor.

最後，當你聽到你血型後面有 「陽性」 這個字，代表你有叫做 Rh 因子的額外抗原。

A universal blood donor has none of these antigens which makes someone with O negative blood very valuable.

一般的捐血者不會有這些抗原，這讓擁有陰性 O 型血型的人非常珍貴。

So what's your blood type? Let us know!

所以你的血型是什麼？讓我們知道吧！

And if not, you should go ahead and ask us a question that you want answer, because it might become a Life Noggin video.

如果不知道的話，你應該來問我們一個你想要知道答案的問題，因為那有可能變成一集 Life Noggin 的主題。

I'm Blucko, this's been Life Noggin, I'll see you on Monday with a brand new video.

我是 Blucko，這是 Life Noggin，星期一會有一部全新影片，我們到時候見。

Don't forget to keep on thinking!

別忘了要持續思考！