你了解自己吗？关于身体的12个神奇事实

Do feet really get bigger with age?

脚会一直随着年龄长大？

It’s certainly possible: After years of wear and tear, tendons and ligaments in your feet may weaken. This can cause arches to flatten, which means feet get wider and longer. It won’t happen to everyone, though—people who are overweight, who get swollen feet or ankles, or who have certain medical conditions, like diabetes, are more prone. If it does happen, the average gain is about one shoe size by age 70 or 80.

这是有可能的：经过多年的磨损，脚部的肌腱和韧带会有损耗。这就会使得脚底变平，那么脚就更宽更长了。但不是每个人都会这样，那些很胖、脚或者踝关节浮肿，又或有过某种病症比如糖尿病的人更容易出现这种情况。一般来说到了70或80岁脚会大一码。

What’s with that stomach-in-your-throat feeling on roller coasters?

做过山车时为什么有胃到喉咙眼的感觉？

Your insides are actually shifting! When a coaster comes over its crest, slows for a second for added torture, and then plummets downward, the seat belt keeps your rear in place, but some loosely connected internal organs—like your stomach and intestines—get a little “air time.” You’re not damaging your innards by riding even the craziest of coasters (everything returns to its proper place), but your nerves detect the movement, which registers as though your stomach has jumped into your throat.

你的体内在翻江倒海！当过山车到了顶端，减速那一秒钟会加重体内的折磨，随即骤然落下，座位安全带能保持你的屁股在原位，但却无法照顾到体内的器官，比如胃和肠道就会有点“飘飘荡”了。其实玩最疯狂的过山车也不会损坏你的内脏（它们最后会回归的），但是你的神经能感测到运动，就会让你觉得胃都跑到喉咙眼来了。

How come women always seem colder than men?

女人为什么总比男人感觉更怕冷？

The fairer sex has a higher percentage of body fat and conserves more heat around the core. That helps keep vital organs nice and toasty but not the extremities—and when your hands and feet feel cold, so does the rest of your body. Plus, research suggests that women have a lower threshold for cold than men. When exposed to the same freezing temperature, the blood vessels in women’s fingers constrict more than men’s do, which is why they turn white more quickly.

女人体内有更高的身体脂肪比例，也会在体内储存更多的热量，这能保持核心器官的运转，但不包括四肢。如果你的手脚感觉冰冷，身体的其他部位也是如此。另外，调查显示女人寒冷的临界值比男人低。在相同温度的严寒环境之下，女人手指血管的收缩度比男人要大，所以它们会迅速变白。

Is “old-person smell” real?

老年人的体味是真的么？

Yes. But there’s also a distinctive middle-aged-person smell and a young-person smell, according to a recent study. The research found that older people have a less intense—and more pleasant—scent than the middle-aged folk and young whippersnappers. Not what you expected, right?

是真的，但近期研究表明中年人和年轻人身上的味道也是有区别的。调查发现相对中年人和青年人来说，老年人的体味不那么强烈，反而相对温和。和你想的不一样吧？

Why does room-temperature coffee taste so bad?

常温的咖啡为何这么难喝？

The temperature affects flavor. Researchers in Belgium found that certain taste bud receptors are most sensitive to food molecules that are at or just above room temperature. So hot coffee may seem less bitter (and, in turn, taste better) because our bitter-detecting taste buds aren’t as sensitive when coffee is hot. Odors influence flavor as well, so even the most bitter hot coffee may taste delicious because of its pleasant aroma; room-temperature coffee doesn’t smell the same.

温度影响口感。比利时的研究者发现，某些味蕾会对处于室温的食物分子更加敏感。由于我们品尝苦味的味蕾在高温度时并不十分敏感，相对而言热咖啡似乎不那么苦啦（当然口感更好）。气味也会影响口感，所以即使是最苦的热咖啡，也会因为它的香气让人觉得美味，而室温咖啡就没这个香气了。

How come you wake up at night to urinate but not to do anything else?

为什么半夜醒来只想小便？

Because the sophisticated, intelligent neurons in your gut that control colon contractions, which push out waste, are also influenced by your body’s circadian rhythm, the internal clock that wakes you when it’s light out and makes you feel sleepy at night. So most people don’t have the urge to empty their colon in the middle of the night. On the other hand, the bladder, which acts a reservoir for the continuous flow of urine produced in the kidneys, can stretch only up to a certain volume before you gotta go. Normally, you can sleep six to eight hours without having to urinate, but certain medical conditions or drinking too much water before bed can wake you to use the bathroom at night.

这是因为控制着结肠收缩的复杂敏感神经元，也会受到人体生理周期（也就是排便规律）的影响，白天生物钟会让你醒来，晚上会让你睡觉。到了半夜，大部分人并不会急着去排便。另一方面，膀胱一直都储存着肾脏排泄出的不间断的尿液流，到了一定的容量，你就需要上厕所了。一般说来睡眠六到八小时是无需小便的，但某种病症或是睡前多喝水则会使你起夜了。

Why do we have fingerprints?

我们为什么有指纹？

Many experts think it’s to improve grip, but a British study from a few years back suggests otherwise. Researchers found that a fingerprint’s ridges actually made it harder to hold flat, smooth surfaces, like Plexiglas, because they reduced the skin’s contact area. Instead, they think our prints might help wick water off our fingertips or allow our skin to stretch more easily, which can protect it from damage and help prevent blisters. Other scientists have suggested fingerprints could improve our sense of touch. What we do know for sure is that no two people’s fingerprints are the same, even among identical twins.

有的专家认为这会增加在抓取时手上的摩擦力，但最近几年英国的调查显示并非如此。研究者发现指纹的脊状反而使人们难抓平滑的表面，比如树脂玻璃，因为指纹减少了皮肤的接触面积。他们反倒认为指纹有可能是能防止指尖的水分流失，或使得我们皮肤更易吸收水分，从而保护皮肤防止起水泡。其他科学家还认为指纹能提高我们的触觉。目前我们确切知道的是：每个人的指纹都与其他人的不同，就算是双胞胎也如此。

Can achy joints really forecast the weather?

关节疼痛真的可以预测天气？

Maybe. A change in barometric readings may be part of the reason: Atmospheric pressure often drops right before bad weather sets in; this shift could cause body tissue to expand, which can lead to swelling and pain. The effect is slight, but people who have arthritic or inflamed joints may detect the difference. Temperature may have an impact too: In 2007, researchers found that every ten-degree drop in temperature corresponded with a small increase in osteoarthritic knee pain.

也许吧，气压变化有可能是一部分原因：坏天气来临时，气压往往会降低，这会导致机体组织扩张，会让人感觉疼痛。这种影响是十分轻微的，但如果有人患了关节炎又或关节受伤，影响或许会增大。温度也是一方面原因：2007年，研究者发现气温每降低10度会增加膝骨关节炎的疼痛程度。

Why does holding your breath help with hiccups?

为什么憋气能治打嗝呢？

It’s thought that if you build up carbon dioxide in your body (by not exhaling), it will help stop your diaphragm from spasming, which is what causes the hiccups. When your diaphragm contracts involuntarily, it forces a quick intake of breath that’s suddenly stopped by the epiglottis. That closure is what causes the hiccup sound.

有人认为如果你憋住了二氧化碳（不呼气），就能让你阻止你的隔膜痉挛，这也就造成了打嗝。如果你的隔膜开始不自觉痉挛，会迫使你快速吸一口气，然后受到会厌的阻挡。会厌就是打嗝声音发出的地方。

What makes my stomach growl?

为什么胃会咕噜咕噜叫？

It can be the sound of your digestive juices churning and stomach muscles contracting as they get prepped for food. To avoid those often poorly timed and embarrassing sounds, eat smaller meals more frequently.

这是你胃液翻转的声音，胃部肌肉仍像消化食物一般蠕动时发出声音。要防止这些令人尴尬的提醒饥饿声音，就少吃多餐吧。

Why do I sometimes get side stitches when I run?

为什么跑步时会胸口疼？

Your diaphragm gets stretched, pulled, and pounded during a run, which can cause that sharp, stabbing pain at the lower edge of your rib cage, usually on the right side of your body. To help the pain pass, slow down and take more controlled, easy breaths.

跑步时你的隔膜伸展拉长以及变重，这会导致胸腔有种剧烈的疼痛感，且往往在身体右侧。要减缓疼痛，那就放慢速度，呼吸均匀。

Why does armpit sweat smell worse than sweat from other places?

为什么腋下流汗的气味比其他部位难闻？

Your body has two kinds of sweat glands. Most of those on your arms and legs secrete a mix of water and salt. But the glands in your armpits (as well as your groin) release an oily substance, which bacteria love. It’s actually the bacteria eating the oil that releases the telltale stench.

身体有两种汗腺。大部分是在手臂以及腿部，分泌的是水和盐分。而腋下（以及腹股沟）处的汗腺会分泌出油性物体，也是细菌的最爱。所以实际上是细菌吞噬油脂时发出的信号啦。