The human body is a crazy thing. After evolving for about 6 million years, our bodies that include 206 bones, a couple gallons of blood, around 600 muscles and much more, are capable of incredible things. We might not all be climbing Mount Everest or competing in the Olympic Games, but every single one of us has a body that is working incredibly hard to keep us alive. And while we spend our entire lives in these fascinating skin suits, many of us don’t actually have a great understanding of how they work.
That’s why one Reddit user, Alwaysclimbing5, reached out asking others to share cool facts about the human body that a lot of people don’t know. Readers chimed in with fascinating information, including anything from how we can be born with extra ribs to how sensitive our noses are to the scent of rain, so we’ve gathered the most interesting responses down below for you to read, as well as an interview with Dr. Scott Ross about some of the craziest things he knows about the human body. We hope you’ll enjoy your daily dose of biology and that you learn something new about yourself while you’re here. Don’t forget to upvote the facts that really blow your mind, and then if you’re interested in finding out even more about our bodies, check out this Bored Panda piece next.
#1
Lactose intolerance is a normal gene. Being able to drink milk is a mutation.
Image source: Oliver-garden, Pixabay
#2
5% of people never get a headache. F**k those people.
Image source: lilranter, Edward Jenner
#3
If we were an RPG character, our main stat would be endurance.
We are, by animal standards, hellishly undying and unrelenting terrors, these Terminator-esque nightmares that just DO. NOT. STOP.
So ancestrally we are persistence hunters. That is, our main tactic for catching prey without fancy weapons was to just run them down, especially in our way-back home of the African desert. You can still see it, all over the human body.
We are nearly hairless. This lack of insulation means better heat dissipation. We have a *ton* of sweat glands, next to other mammals. Again, heat dissipation. Another one is our two-legged gait – walking for us is technically just a series of controlled falls. We let gravity do half the work, and as a result use up fewer resources and generate less heat (quadrupeds, on the other hand, have to do more work with more legs).
I mean, imagine being a more-or-less gazelle of half a million years ago. You’re eating, doing your thing, when this predator arrives, so you run off. Now most predators, they’ll only chase for a short distance and then call it a day (watch cats, for instance). But this one… here he is again. So you run. He returns. You run again. He returns. You’re getting hot – you have to stop and pant to lose heat, but he just keeps jogging. You run. He keeps coming. You’re tired – you’re fast, but not for very long, and this stretches your limits.
Eventually you just lay there, exhausted and heat-stunned, and this ludicrous hairless monkey just jogs on over and kills you.
That’s our claws, our sharp teeth, even without our technology and tool-making. We simply don’t stop.
Image source: vault13rev
#4
When you are exhausted and go to bed your body shuts down faster than usual. That ‘jerk’ or ‘kick’ that your leg makes is a signal from the brain to make sure you are not dying. Your body takes a a while to slow down to sleep but whilst exhausted your brain double checks to make sure you are still alive by sending a message from your brain to to the bottom of your body to check if your nerve sytem is still functional. This is usually a quick kick of your predominant leg.
Image source: diego_le_blanco
#5
Natural redheads require increased doses of anesthesia, due to some connection with the mutated melanocortin-1 receptor. I’m a natural redhead myself, and developed a fear of dentists because I’d always feel what they were doing!
Eventually I had an issue that couldn’t be ignored, and had to find a new dentist. At my first visit he took one look at me, and said “You’re a real redhead, huh?” “Yup.” “(Hygienist), get me 4x the novocaine!” I knew I’d found my man, and he’s been treating me ever since… also shed my fears, since dental work is much less unpleasant when you’re actually numb before they start.
Image source: LollyHutzenklutz
#6
Breastmilk will produce antibodies to help baby fight off disease. It’s thought that’s babies saliva enters the nipple, mums body tests for any undesirable bacteria, then produces milk to help fight it off.
For this reason, it’s not unusual for breastmilk to look different when baby is sick. Sometimes very dark yellow and thick, almost like colostrum. It also contains different hormones depending on the time of day, and is antibacterial. It is a living liquid
Image source: LeeLooPoopy
#7
Really late but I discovered this thing during my thesis.
We were researching patients with neurological problems and people who had brain injuries and we found a woman in her 30 that had had part of her brain removed. More specifically the area that activates when you move your body.
Well she was moving and talking with just some minor missteps and theoretically it was not possible, she was paralyzed in the first 3 months after the operation (she was caught in a car accident if I remember correctly).
We were trying out a new scanner for the brain and we found out that an area of the brain that wasn’t supposed to work and control the movement was doing just that. The occipital area (usually controls the vision) was now working as a motor control area.
The brain is really amazing…
Image source: yourteam
#8
When were in an unfamiliar environment we sleep with half our brain at a time kinda like sharks and that’s why we wake up easier.
Image source: creeperedz, Ivan Oboleninov
#9
I work in an ER and a guy came in because he had non-stop hiccups for six days. Every 45 seconds or so he would hiccup. He was going insane because he couldn’t sleep or focus and had a hard time eating.
After running tons of tests and almost giving up hope on helping this guy, one of the nurses looked in his ears and found q-tip cotton stuck inside and as soon as the cotton was removed, the hiccups stopped completely.
Dude was so relieved he cried.
Image source: cms0603, Rohan Dalal
#10
When we get sunburn, that’s not the heat of the sun that’s hurting us most of the time, but it’s little skin cells killing themselves to protect us from skin cancer.
Not so cool if I think about it.
Image source: datboiakon, Tora Chu
#11
Archaeologist here.
You can give birth after you’ve died.
Occasionally we will come across a really confronting burial where the skeleton of an unborn child is halfway through its mothers pelvis. Generally what happens is the woman has died before giving birth and after burial a build up of gasses from decomposition forces the baby out. We refer to this as “coffin birth”.
Image source: hetep-di-isfet, Lisa
#12
Eye immune privilege: Your immune system doesn’t know your eyes exist. Theres a chance that if you get an eye injury or an infection near your eyes the immune system will think your eyes are a foreign body and you’ll go blind.
Image source: Kubrick_Fan, Pixabay
#13
The bone that supports your eyeball, called the orbital floor, is paper thin and has a large empty cavity, called the maxillary sinus, on the opposite side. When you get hit hard in the eyeball, instead of your eyeball itself rupturing, the bone underneath your eye breaks, which is called an orbital floor fracture. This releases the pressure from the impact and saves your eyeball. If you crush a beachball against a concrete wall, you can pop it, but if you try crush it against a styrofoam wall, the wall breaks but the beachball is fine. An amazing evolutionary adaptation to protect your eyesight.
Image source: ddsmd
#14
You mostly breathe out of one nostril at a time, and the ‘dominant’ nostril switches every hour or so.
Image source: thecuriousdigest, Frederico Dionisio
#15
You just need to focus on the time you want to wake up and our hypothalamus would wake us up at the exact same time.
Image source: whosharjot_singh, Acharaporn Kamornboonyarush
#16
Women are actually programmed to forget the pain of child birth after a few months or so. If this didn’t happen, most women would only end up having one child, which would eventually lower the population.
Image source: Sqwoopy, freestocks
#17
You can see your nose all the time, your brain just chooses to ignore it.
Image source: GustavGarlicBread, Tima Miroshnichenko
#18
We have an internal regulator that prevents us from using our full strengh. Or muscles usually only work at about 60% max of what we are capable off.
In extreme life and death situations these regulators stop and we are able to use our full strengh. This is how the parts where people tipped over cars and similar come from.
These regulators are because at full strengh we heavily damage our bodies. Essentially, you could lift something to the point where it is either lifted or your arm just breaks instead. I believe there has also been someone who ran so hard his leg broke.
Image source: Mad_Maddin, samer daboul
#19
If you lose a hand and then have it reattached, even if all the feeling and movement ability comes back, your skin on that hand will never get wrinkly in water again. It’s lost the ability to do so.
Also, the reason our hands get wrinkly after too long in water is to give us more grip on slippery surfaces.
Image source: LeaninKeenan
#20
Your liver can regenerate, and much faster than you think. I had a quarter of my liver removed, and a month later it was back.
Image source: Rock_Robster__
#21
A small percentage of people are “Super Sleepers” and are fully recharged after 2 to 4 hours of sleep each night. They get to burn the candle at both ends!
Image source: lokensnarm
#22
Your heart rate increases about a minute before partaking in exercise. It is known as the anticipatory rise and happens involuntarily.
Image source: Wizzkidsjay, Ketut Subiyanto
#23
The microscopic mites living on your face feeding off the oil glands.
You can’t see them, but they’re there. They are microscopic mites, eight-legged creatures rather like spiders. Almost every human being has them. They spend their entire lives on our faces, where they eat, mate and finally die.
There are two species of mite that live on your face: Demodex folliculorum and D. brevis.
It’s cool cause that means I’ll always have some friends with me.
Image source: alienandro, Pixabay
#24
Blind people process Braille in their visual cortex. Amazing example of neuroplasticity.
Image source: Sydney2London
#25
When you first set your sight on the seconds of a watch (or anything with a rapid regular movement) you will sometimes feel like the first second lasts a little bit too long. It’s because your brain replaces the motion blur that happens when you moved your sight from wherever it was to the watch with a fixed image.
And the cool thing is that it replaces it “after the fact”, or rather gives you a very short false memory that you were already watching the watch while your eyes were moving, making that first second seem longer.
It’s called Chronostasis.
Image source: Wdebense
#26
Some humans do not feel any pain and have to be closely monitored because they can get sick/injured so easily and not even realize.
Image source: AidansSeenSomeS**t, Thirdman
#27
When you’re a baby you have several defence mechanisms that stop you from drowning: you reflexively hold your breath when underwater and your heart rate and consumption of oxygen decreases, allowing you to last significantly longer underwater than an adult.
Image source: natpri00
#28
A baby’s body has about 300 bones at birth. These eventually fuse (grow together) to form the 206 bones that adults have
Image source: Dee_Jay77
#29
The human body contains enough fat to make seven bars of soap.
Image source: obliterator101, Valeria Boltneva
#30
We are, by cell numbers, more bacteria than human.
Image source: sandysanBAR, Tima Miroshnichenko
#31
Your hands and feet alone account for more than half of all the bones in your body (106/206)
Image source: gianthooverpig
#32
The femur is stronger than steel and concrete.
Image source: anon, Polina Tankilevitch
#33
Cutting the corpus callosum ( connects two brain hemispheres) can produce some freaky results. Such as your hand doing s**t that your conscious mind isn’t aware of, writing a sentence or scratching an itch without knowing for instance.
Image source: anon, Andrea Piacquadio
#34
We breathe out most of our weight during weight loss.
Image source: EpsilonRider
#35
Amniotic fluid is mostly baby urine.
Image source: purpleRN, Anastasiia Chepinska
#36
Your bones are always wet.
Image source: verifiedone
#37
You’re taller in the morning than the rest of the day/night.
Image source: crazynights87, charlesdeluvio
#38
Babies don’t have full color vision until 5 months old!
Image source: pretendimgoodatthis
#39
There is a muscle, called palmaris longus, in the forearm missing in about 10% of the population. You can easy test if you have it by putting your pinky and thumb together, while holding your palm facing up, and flex the hand upwards. If 1 tendon is standing out more than the others that’s palmaris longus.
Image source: johigangan, wikimedia.commons
#40
We have a bunch of microplastics in our body.
Image source: gayboyuwu, Brian Yurasits
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