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“What Is A Fact About The Human Body That Not Many People Know About?” (50 Answers)
The human body is everything that makes up, well, us. However, there are plenty of fascinating things we don't know about it, or rather, ourselves.
Once you look closer, dive under the surface of the skin, explore the inner workings of the biological systems that ensure our everyday life, you just can't help but admire the marvel that you really are.
To learn more about our bits and pieces, Redditor u/Zenssei made a post on r/AskReddit, asking other platform users to share some facts about the human body that not many people know about. Their call to action was immediately answered.
u/Zenssei said the idea for this post came to them pretty naturally. "I was just watching TV, thinking of [something] I could post on r/AskReddit," they told Bored Panda.
"I have learned quite a bit from the comments such as there is a right and a wrong way to swallow, or that about 20% of people have a bone ridge on the roof of the mouth... It was fun reading through the replies."
As of this article, the post already has received over 56K upvotes and 23K comments, and has become one of the coolest online trivia archives out there!
This post may include affiliate links.
#1
Your brain regulates how strong your muscles are. If your leg muscles were to contract at full strength, they would snap your femur.
Its why people in emergencies on adrenaline can lift cars off children. Your body is capable of great strength, but it could also severely damage you, so your brain keeps you a weak, soft bag of jelly.
#2
When doing surgery where the doctors have to take out some organs, when placing them back, they don't have to be put back In the exact position there meant to be, your body kind of just, moves the organs into the correct position after the surgery
There are many ways we could look at the human body. "On an evolutionary scale, sometimes we are similar to animals, and sometimes we're not," general practitioner, medical researcher, and founder of PrimeHealth Clinical Research, Iris Gorfinkel, M.D., told Bored Panda. "We're symmetric, [our] basic body structure is similar; we have what's called homologous bone structure. In other words, you can find exact similarities between humans and other animals and how our bones are put together."
"Even our muscles and heart and vascular systems are similar. Our lungs are often similar too. [As well as] the fact that there's a long tube from the moment food enters our mouth to the point at which it goes out of our rectum," Gorfinkel explained. "Their breathing is similar to ours neurologically. Urologically (how urine is formed), we're also quite similar. In all of these aspects, we are very similar to animals."
#3
People who live in "extreme" conditions for generations adapt in extreme ways. For example people that live in high elevations often have larger lungs and different blood makeup. Or my favorite is the Bajau people that live on the water and spend a lot of their time diving, their spleens have become 50% larger in order to store more blood.
#4
You hate the sound of your recorded voice because it's missing the low frequency you're used to hearing.
When you talk, you hear your voice as it goes to the air and back to you ear. It also goes through your skull to your ear, and this bone conduction mechanism transmits the low frequencies better than air does.
Your recorded voice only has the air transmitted sound. That causes the dissonance between what you think your voice sounds like, and what it really does. It's also why your voice will (almost) always be higher pitch than you think.
But if we continue to measure ourselves against animals, we inevitably start noticing differences. "Animals communicate across miles of land through subsonic sound, that's true. But human beings, on the other hand, have very complex language systems," Gorfinkel said. "We have introspection—that's another critical difference, [as well as] our creativity and emotions, like joy and sorrow and grief—although grief has been described in some animals, including elephants, wolves, and sea lions. But the biggest difference that makes us humans a complete and utter separate category within the animal kingdom, is our ability to have an imagination, to use language in such a complex way, and to hold fictions in our mind."
The comparison that Gorfinkel thought of on the spot illustrates her point on a meta-level. "Let's just say the lion is the guardian spirit of our tribe. He still could never convince a monkey to give him a banana by promising the little guy, say, an unlimited supply of bananas in monkey heaven. So our ability to create and believe in collected fiction, that's what makes human beings really different."
#5
The heart smells like mushrooms.
Source: I’m a cardiac anesthesiologist
#6
Humans have, on average, just as many hairs on their body as chimpanzees, human hair is just a lot shorter and finer.
Some parts of our body, however, remain unknown even to science. Take the human brain for example. It has approximately 86 billion neurons, woven together by an estimated 100 trillion connections, or synapses. So untangling such a delicate network is a daunting task—we don't know the details of how those cells work, let alone how they come together to make up our sensory systems, our behavior, our consciousness.
"You would think it would be easy [to study the brain], it weighs only three pounds, and three-quarters of it is water and 60% of it is fatty tissue. And you'd also think it's easy because the brain can't feel pain. You know, surgery could be done on it, allowing for easy experimentation, as inhumane as it sounds. But there are several things that make it extremely difficult," Gorfinkel said.
"[Our billions of neurons], connected by trillions upon trillions of synapses in a barrel, is a veritable neuronal forest, and the information is moving at all different speeds, some up to, I think, 250 miles an hour. So even with things like functional MRI [we don't get close to] the nitty-gritty of understanding the very fine neuronal connections that are happening, that really define memory, that define all the complexity that I was just describing: language, reason, creativity, and emotions."
#7
Your eyes have a separate immune system from the rest of your body and in a lot of occasions if your body's immune system finds your eyes, they will assume they are a foreign body and blind you.
#8
Humans are bioluminescent and glow in the dark, but the light that we emit is 1,000 times weaker than our human eyes are able to pick up.
Christof Koch, Ph.D., Chief Scientist and President of the Allen Institute for Brain Science, and his colleagues study the brain on a large scale. But the more they look at many or most cells in the brain rather than just a few, the more they realize that even the parts of neuroscience they thought the field had nailed down are more complicated than anyone had realized.
"There may not be any simple path to understanding complex systems shaped by natural selection,” Koch thinks. "Evolution doesn't care about elegance. The brain doesn't care if you understand it."
#9
When you cry and your nose becomes runny, it's actually your tears.
#10
The reason it's so easy to break your collar bone is because its designed to break.
The way it was explained to me is that its like a circuit breaker. It breaks there to stop the shock of impact getting to your spine
But that doesn't mean we should stop learning. On the contrary. There's plenty we can do as individuals and as a society to get a better understanding of ourselves and in turn, those around us. "Emotional education is sadly lacking in schools," Gorfinkel said. "We teach all kinds of useless things. And I hate to say it... They're not useless, but they're not as relative to us as understanding our emotional selves."
The doctor said there is precious little time devoted in schools to understanding emotions, such as anger, humiliation, shame, guilt, and what to do when we face them. Instead, they're often presented as something negative we need to control, as opposed to being contextualized. These emotions can actually help us, show us the path towards what needs to be done next. "They shine a light on how we need to manage our lives better," Gorfinkel explained.
"That is something that has long bothered me. Emotional education is, for the most part, not focused on; we focus on physical education, we focus on [general] education [like] mathematics, physics, chemistry, biochemistry, whatever it is, but a lot of the time, the most critical part that will determine our happiness, and our productivity is completely overlooked."
Because of that, we have to do it ourselves. "Just make the most of picking the low lying fruit," Gorfinkel said. "I'm talking about [things like] sleep or finding the right amount of stress in your life—stress is an interesting thing. Too little stress is actually bad for a person, there's a sweet spot when it comes to stress. And it's kind of a bell curve, right? That if you have too little, there's not enough stimulation. And a person does not approach self-actualization. Even though stress is roundly considered a negative thing, in fact, a little bit, just the right amount is a positive thing. Of course, it can turn into a very negative thing if there's too much. But finding the sweet spot of stress is probably the best tip that I could give."
When you think about it, the Internet is a beautiful thing. One moment, u/Zenssei is chilling in front of their TV, the next, tens of thousands of people are teaching one another about the human body. More of this, please.
#11
Our brains make up, on average, around 2% of our body weight but consume 20% of our caloric intake
#12
Your body will reduce your muscle strength to protect your spine.
Stand on flat ground, hold your arms out in a t-pose, and have a friend push down on your hand while you try to hold it in place. That's your control, how strong you actually are.
Now, remove 1 shoe (or put a book under 1 foot) and repeat with your hips askew so your spine isn't straight. An inch is all it takes.
Your strength will be reduced to the point that your friend can use a single finger to push your hand down.
#13
Alzheimer’s disease isn’t just gradual loss of memory. It physically exists in the brain. It’s a physical substance that attacks the brain. Like, if you were able to open the skull of a person suffering from Alzheimer’s disease to take a look at their brain, you would actually see this sticky, fibrous, grey physical matter overtaking their brain.
#15
You will sooner die from lack of sleep than lack of food.
You can live, depending on your current body fat and health level, for months without food. Estimates are you that you will die for lack of sleep within 2 weeks
#16
The appendix is not a vestigial organ. It actually protects good bacteria in the gut. You can live without it, but it’s not just chillin’ in there
#17
Scars are not made of "permanent" tissue (they're held together by collagen) and are in a constant state of repair. This repair is facilitated by vitamin C (amongst other things). Yes, this means that people with scurvy (from vitamin C deficiency) will see all their old scars reopen into fresh wounds.
#18
Some women can feel the exact moment an egg is released from the ovary during ovulation. Feels like a little pop just on one side. Pretty neat
#19
Humans are one of a few species of mammal that oddly don't produce their own vitamin C due to lack of a certain enzyme. Other mammalian species who exhibit this mutation are those contained in the main primate suborder Haplorhinni (monkeys, apes, tarsiers), as well as bats, capybaras, and guinea pigs.
All other mammals produce vitamin C in the liver.
Bernd Herbert 3 years ago
Fun Fact: Primates can't produce the necessary enzyme L-gulonolactone oxidase because of a mutation that probably happened 58 to 63 million years ago. It is believed that this very negative mutation survied because of the arboreal living conditions with plenty of fruity Vitmain C sources. Anyhow, another proof of common ancestry of the primates as we all have that same mutation in our genes.
#20
You can calm yourself down by splashing cold water on your face to trigger the mammalian diving reflex.
#21
You can grow a new human being faster than most missing toenails can grow back
Jo Johannsen 3 years ago
Hmmm... lost a toenail in an accident, and it was back in about six months vs. nine months for preggers.
#22
If you carry a lot of unprocessed trauma, it can cause psychosomatic autoimmune diseases.
Nikki Sevven 3 years ago
Note that "psychosomatic" does NOT mean "imaginary." It means that emotional trauma is translated into physical trauma.
#23
X-rays of childrens mouths are nightmare fuel. The second set of teeth to replace baby teeth are already grown and lodged in their skulls. So you'll see two rows of teeth and its freaky looking. They don't grow in when the old ones fall out, they are already loaded in the chamber waiting to get launched.
#24
The surface area of the lungs is about the same size as a tennis court
#25
If you say haaah your breath comes out warm,but when you say Woooh it comes out cold.
#26
It's possible to pull a jaw muscle while yawning. I found this out the hard way at work one day.
Lauren Caswell 3 years ago
It's possible to pull all sorts of muscles I only seem to have just so I can injure them
#27
Your body must warm fluids before absorbing them, so drinking ice cold water to hydrate is only burning more energy, and you're not hydrating as quickly.
Jo Johannsen 3 years ago
I have always assumed this, and choose ice water to burn more energy.
#28
That there is NOT 20 lbs of toxic poop in your body at any given time. But apparently a ton of people still believe all sorts of ads about some pill or another being able to flush some imaginary "toxins" out of your body like it's going to magically cure you of 20 years of terrible eating and exercise habits.
Jo87 3 years ago (edited)
Well that's not strictly true - because of the shape of the lower intestine and colon, they never really empty fully. It's very rarely 20lbs worth (you would be extremely ill if that was the case) but there's certainly areas that don't fully clean and bad bacteria can build up there. These drinks and pills work by irritating the gut so badly that everything gets removed, including good bacteria so they are not a healthy option, but they do technically do what they claim.
#29
Apparently not everyone knows that women grow a new organ while pregnant.
In addition to growing a child, they grow the placenta.
Helena Houzarová 3 years ago
Only part of the placenta is grown by the mother. The rest is grown by the baby, as evidenced by father's DNA in it. Fascinating.
#30
39% of people have an extra bone in their knee. 100 years ago only 11% of people had this bone.
#31
Your brain continues to try to revive the body long after the heart has stopped. In some cases 30 hours later there has been found brain activity trying to make repairs to bring the body back. This is used to indicate time of death in murder victims.
Sandy Kavanaugh 3 years ago
How could a brain deprived of oxygen and glucose for so long function on any level?
#32
The proportion of your vision that is actually in sharp focus roughly equates to the size of your thumbnail at arm's length. The rest of it is just your visual cortex filling in the blanks.
#33
In children under 11 (for some reason), cutting off the fingertip from the last knuckle will result in complete regeneration of the finger in 100% of cases, assuming the naibed is intact. There's no explanation for why this happens, why it only happens to children under 11 and why it can't be sequences to fully regenerate / grow organs. It also occurs in many animals, as observed in test rodents.
I learned that in science class in grade 8 and my dad called me a liar. I showed him my science textbook and he threw it away and said it was fake.
#34
You can live "normally" with half your brain. In some severe drug resistant epileptic syndrom in young kids, the only option to stop the seizures is to remove a complete brain hemisphere.
After a while, with proper reeducation and all, the children can go on to have a normal life without cognitive deficit. They will have a limping, blindness from one eye and a very weark arm but can lead a normal life and not end up cognitively impaired.
One of the earliest sign of alzheimer's disease, before the memory loss, could be the loss of the sense of smell. It's also the case with Parkinson disease.
Our brain looks wrinkled because it is actually "folded" inside our skull in order to fit a maximum of surface and thus neurons & cell communications. Some animals like rodents have a completely smooth brain.
#35
Every minute you shed over 30,000 dead skin cells off your body
#36
The reason it feels weird when you or someone touches the inside of your belly button is because the nerves actually go to your spinal cord. These nerves lie at the same level that relay signals to your urethra and bladder. So when you feel like you have to pee when you touch the inside of your belly button, that's why.
Sandy Kavanaugh 3 years ago
I can't take it. That's why I don't wear elastic in my pants. Can't stand it against my belly button!
#37
You can poop out of your mouth if your intestines get backed up enough. It's like vomit, doesn't look like actual poop per se, but it's still disgusting.
#38
Humans have stripes, we just normally can’t see them. They’re called Blaschko’s lines and form along the paths of embryonic cell migration. The stripes are sort of U-shaped down our front, V-shaped on our back, wavy on the head and face and we have basic, simple stripes on our extremities.
#39
Each one of your eyes has a blind spot where the optic nerve exit your eye into your brain. You can't see it because your brain tricks you not to see, it covers the spot with some made up image of what it thinks fits better with the rest of it.
#40
We're the best marathon runners in the animal kingdom and can win a marathon against any animal out there.
Refugee Pups 3 years ago
AND - that's why we pair with dogs so well, because they're marathon runners also, so we could hunt prey together by wearing it down over time rather than catching it in a sprint or a super quick movement the way many animals do - alligators, bears, birds, snakes, spiders, oh, and obviously... cats ;). That's true!
#41
The average adult has 22 square feet of skin. Perfect size for a nice rug.
#42
Human eggs are small but big enough to be visible to the human eye
#44
Your brain likes stimulation, if it doesn't get any it will make some up, some people are more sucepticle to it then others, the colors you see before you fall asleep are a common mild occurrence, there are several classes of these hallucinations, closed-eye visuals, which are caused by leaving your eyes closed for a long time, hypnagogia, which is caused by the onset of sleep, prisoners cinema, which is caused by looking into a dark place for a long time, ganzfeld effect, which is caused by blocking out all external stimuli, and Charles bonnet syndrome, caused by sight loss.
Most are these are simple phosphenes but some can be whole imagined scenes, or more abstract fractal-like imagery
Laugh or not 3 years ago
I get the fractal imagery. It is very pretty. Box that I know it is because my brain is bored, I will try to stimulate it more.
#45
When you have a bowel movement, your heart rhythm shifts temporarily due to a vagus response. The reason Elvis died on the toilet was because his heart was beating 200+ bpm and the quick rhythm change caused a myocardial infarction. People with low heart rates have been known to pass out on the toilet because their bodies can't handle the shift.
It's also why EMTs will absolutely not let you use the bathroom before getting on the ambulance. Especially if the bathroom is a standard 5'x8'.
Refugee Pups 3 years ago
What do the dimensions of the bathroom have to do with poop-based heart attacks?
#47
It only takes about 15 pounds of force to rip off a human ear
#48
Synovial joint fluid is the most frictionless stuff on the planet (unless they've synthetic'ed something up that recently.)
Lauren Caswell 3 years ago
Is this the stuff people thought others were trying to steal from them?
#50
If you faint at the sight of your own blood you may have an oversensitive vasovagal response. The theory is that this developed as a survival mechanism, kind of like an opposum playing dead.
What do you think ?
respulero 3 years ago
those are interesting. I hate that tomorrow i will have already forgotten all of them
Vicky Z 3 years ago
Interesting but many are inaccurate or need more explanation because they are not well written
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Karin 3 years ago
Who are these posters and what are their credentials? What are their sources? Some of these "facts" are just BS. Please don't believe everything you read on the internet.
Leo Domitrix 3 years ago
The TLDR version of what i said. Agreed. they're wildly misleading, interpreted very oddly at best, or just weirdly click-baity.
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Fish Boden 3 years ago
A few of these are nonsense. I dearly wish a bit more fact checking went on.
respulero 3 years ago
those are interesting. I hate that tomorrow i will have already forgotten all of them
Vicky Z 3 years ago
Interesting but many are inaccurate or need more explanation because they are not well written
Load More Replies... Karin 3 years ago
Who are these posters and what are their credentials? What are their sources? Some of these "facts" are just BS. Please don't believe everything you read on the internet.
Leo Domitrix 3 years ago
The TLDR version of what i said. Agreed. they're wildly misleading, interpreted very oddly at best, or just weirdly click-baity.
Load More Replies... Fish Boden 3 years ago
A few of these are nonsense. I dearly wish a bit more fact checking went on.
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