comes to pain?

穿過一個銅板大小的洞。另一方面，男性則抗議就算是 輕微的碰撞到他們的蛋蛋都會使男人全身無力。

On the one hand women are left with the task of fitting a watermelon sized

所以誰比較痛?生小孩還是被踢蛋蛋? 網路上有流傳一個說法聲稱 人體可以承受45DEL的疼痛，而母親分娩的疼痛

object through a coin sized hole. On the other hand, males protest that even the

則高達57DEL 相當於一次斷裂20根骨頭的疼痛。 而被踢到蛋蛋的疼痛指數則有9000DEL。

slightest nick of their family jewels can leave them incapacitated.

光是男女兩方都會承受超越人體極限的 疼痛不合邏輯之外，實際上這個DEL單位

So which hurts more, childbirth or getting kicked in the balls?

甚至根本不存在。有一個從拉丁文的疼痛DOLOR衍伸出來的 疼痛單位稱為DOL，這個話題我們稍後會再討論。

Before we begin there is a rumor that is circulating the internet claiming that

要真正評估這個問題，我們首先必須了解什麼是疼痛， 這不是件簡單的事。 你的體內有一種特殊的神經細胞稱作傷害感受器

the human body can take up to 45 del units of pain and yet a mother feels

來傳遞疼痛反應。 其他的神經細胞是對溫度與壓力有反應， 傷害感受器只會在疼痛超過某個程度之後才會有反應。

up to 57 del of pain during childbirth,

這些感受器很快地傳遞訊號到脊隨與大腦 瞬間產生明顯的疼痛，讓你可以迅速對疼痛做出反應

which is apparently equivalent to 20 bones being fractured at once.

而其他的神經傳遞比較慢而且得到的反應較輕微且持久 男性的睪丸是一個從體腔內向外移出的器官

The claim then goes on to suggest that being kicked in the balls brings more

在這裡你可以看看我們之前的影片裡的解釋。 其他的臟器譬如肝臟是感覺不到疼痛的

than 9000 del of pain. Now apart from the absurd logic that both of

而睪丸上覆滿許多傷害感受器，因此是極為敏感的。 畢竟你的蛋蛋是很重要的東西 此外，睾丸神經與胃的許多神經有連結

these events can surpass the alleged human limit it, actually uses a unit of

此種迷走神經又與大腦的嘔吐中心有直接連接， 這就是為什麼被擊中之後整個腹部都會疼痛的關係。

pain, the del, which doesn't even exist. There is a unit of pain once devised

事實上睪丸幾乎沒有任何保護 只會伴随噁心、血壓升高、心跳加快及出汗的症狀。 但是各位先生別開心得太快，即使分娩可能不會對體內器官

called the dol, from the latin word for pain "dolor" but we will discuss this later.

有衝擊，子宫造成的腹脹 也會啟動傷害感受器導致一樣的內臟疼痛 同時演化的結果女性的臀部變得更小

To really evaluate this question we first need to understand what pain is,

而嬰兒的頭部變大。更何况要經歷持續 8小時的噁心疼痛 最重要的是，肌肉跟組織的緊張拉伸

which isn't an easy task.

也會加劇局部疼痛。 所以兩性明顯都很痛，而且都有大量的刺激訊號 傳送到大腦的疼痛中心。 但是這就是問題所在，因为疼痛不單純只是一個物理反映

There is actually a group of specialized nerve cells in your body called nociceptors

很大一部份是個人的主觀認知。 意思就是每個人經歷的疼痛多少都有不一樣的程度

that react to pain.

不只是個體間的差異，你當時的情緒、警覺性甚至 以往的經驗都會有所影響。 就是因為這樣所以很多想要客觀測量疼痛的指數

Unlike other nerves which readily fire in response to normal touch or temperature,

包括前面提到的DOL系統都是失敗收場。 有趣的是，近80％的上肢截肢者遇到

nociceptors will only fire once a certain pain threshold has been passed. Some of

一個稱作幻肢痛的現象。 他們對不存在的手腳仍然會感到疼痛 雖然對這個現象的了解有限，但是很顯然

these nociceptors respond quickly sending signals to the spinal cord and brain

並沒有任何東西可以造成疼痛，但是他們仍有很真實的疼痛感覺 由於疼痛不止是一種刺激，每個人的疼痛經驗都會有所不同

which produce sharp and sudden pain, allowing you to react quickly

可以說生小孩與被踢蛋蛋都 非常痛。 因此我們當作是一個平手，雖然這兩者間有許多

while others transmit more slowly and are responsible for the prolonged dull

不同之處而且有很多變數要去考慮。 在某些情况下男人會承受比較多的疼痛，反之亦然，

ache you feel. For males, testicles are internal organs that have migrated out

總而言之這兩者之間的差異是一個會生小孩 一個會導致你生不出來 還有其他問題想了解嗎?請上臉書與推特。

of the body cavity which we explain in a previous video you can check out here.

訂閱以收看每周的新影片

And well some internal organs such as the liver feel no pain, others like the

testicles are covered with many nociceptors making them extremely sensitive.

Afterall their well-being is of the utmost importance.

Furthermore the testicles are attached to many nerves in the stomach as well as

the vagus is nerve which is directly connected to the brains vomit center,

and this is why when hit the pain spreads throughout the abdomen.

The fact that testicles have minimal protection only strengthens the

accompanying symptoms of nausea, increased blood pressure, heart rate and sweating.

But not so fast gentlemen, even though childbirth may not be facing a direct

blow to any internal organs, the mechanical distension of the uterine

area also triggers nociceptors and causes the same kind of visceral pain.

Also consider that throughout evolution female human hips have become smaller

while babies heads have become larger. And not to mention labor lasts

8 hours on average with a mixture of nausea, fatigue and pain.

On top of it all, tension and stretching of muscle and tissue increase as labour

intensifies creating sharp and localized pain.

Okay, so both obviously hurt and have a lot of mechanical stimulation sending

signals to the pain centers of the brain.

But this is where it gets tricky, because the pain isn't simply a physical

response but rather a partially perceptive or subjective experience.

This means that every single individual perceives pain in a slightly different

way. And not only between individuals but depending on your mood, alertness or even

previous experience pain may affect you differently.

It's for this reason that so many attempts to objectively measure pain have

failed including the dol system which we mentioned earlier.

Interestingly nearly 80% of upper limb amputees experience a

phenomenon known as "phantom limb pain".

That is they feel pain in a limb that is no longer there. And while little is

understood about the mechanism for the pain, it is clear that there is no

particular input to trigger the response and yet they still feel a very real

pain.

As such pain is not a stimulus it is an experience that is different for

everybody. Suffice to say both instances of childbirth and getting hit in the

balls can hurt alot.

So we call this one at tie, apart from the fact that the experiences are

completely different and there is so many variables to consider.

In some instances a man could experience more pain than his female

counterpart and vice versa. The main difference being one results in a newborn

baby, while the other potentially results in a decreased the chance of

having one.

Got of burning question you want answered? Ask it in the comments, or on facebook and twitter.

And subscribe to more weekly science videos.