What’s the most amazing thing the human body does that people have no idea about?

  1. When a pregnant woman receives heart tissue damage, the fetus will send stem cells to repair it.

  2. Everybody else is blown away by the capacity of the brain, while I’m amazed at how the forearm can twist. You have two parallel bones, and your muscles pull them so they cross, which rotates your arm. How crazy is that?

  3. The human hand is one of the most insanely fine tuned pieces of organic machinery on the planet. It contains an absurdly dense amount of nerve cells and special nerve adjustments that make it incredibly sensitive to extremely small signals. Because of this, and the insane art that is the natural craftsmanship of our hands, the human hand has a dexterity for precision that other apes do not have, let alone the rest of the barbaric in comparison animals.

    And you use it to jack off and browse memes

  4. Saccadic masking!

    I’m not an expert at this, but I’ll give the explanation as I understand it.

    Basically if you move your eyes too quickly, your brain will freeze details that should be blurred and process that image, preventing you from actually seeing motion blur. I think you would most likely get sick if you could actually see things blur that much?

    Anyway, a cool result of this would be the “stopped clock”. If you dart your eyes around really fast and then stare at a clock with a second hand, you’ll see one second last longer than it should. This is due to saccadic masking blocking any visual processing.

    Edit: Many of you have mentioned the stopped clock effect is due to Chronostasis instead of Saccadic masking. You could very well be correct, but I believe they’ll similar/related. I always encourage anyone to read rather than take a redditor’s word for it!

    Also, you’re very welcome to everyone who’s happy to have solved a personal puzzle. I love random facts for this reason!

  5. I’ve always thought the resilience of the human body is pretty damn incredible. Your body will fight with every ounce of its being to keep you alive, literally. Your body will digest itself to salvage nutrients for vital organs, your cells will kill themselves if they can tell there’s something wrong with them for the good of the rest of the body, and you have so many reflexes that you wouldn’t even begin to understand until they actually kicked in when you go into survival mode. The instinctive drowning response, for example. Every part of your body is focused on keeping your mouth above water for air. My personal favorite response is fight or flight. Normally your muscles are limited in how much power they can exert so they don’t get hurt excessively during routine tasks like exercising. When your adrenaline surges, that limit is gone. Your muscles will work as hard as they possibly can without restraint, and you don’t feel the pain of overexertion either. This is where we get those stories of people lifting cars off their children – hysterical strength.

    What your body can do in life or death situations is pretty fucking cool.

  6. Your body usually kills one cell a day that would have turned to cancer. Usually.

    Usually….

  7. Breastmilk actually changes it’s composition to meet the individual nutritional needs of the baby(ies) feeding from the breast. For example, if mom is nursing a toddler (who is more prone to short little “drive by” nursings) the child get more bang for their buck and gets a full session’s worth of proteins, fats and vitamins in their one minute fly by the same as a 3 month old gets in their 25 minute session. As they get older, the quantity of vitamins, fats and proteins changes as well to meet their individual needs. This is even true if mom is tandem nursing two babies of different ages: the milk actually customizes itself to ensure they both get exactly what they need, and the amount of milk she makes is dependent entirely on how much stimulation she gets (ie. the more the baby nurses at the breast, the better supplied they are. This is why using bottles and pacifiers mucks up someone’s supply: the baby wastes all their suckling needs somewhere else).

    Even cooler, the milk makes antibodies for the viruses mom and baby are exposed to and fighting off. I always thought the coolest part in particular was that before the mom even know she or her baby are sick, her milk is already creating medicine (antibodies) to treat her child. It’s like a built-in vaccine that is constantly being updated to fight off the latest bugs. This is the main reason why breastfed babies are better equipped to fight off both short term illness and long term disease (like respiratory illness, asthma, allergies, etc).

    And it comes in a real pretty container, too.

  8. My dentist told me once that gums heal super quickly. That when you have a cut or something in your mouth it heals faster than a cut on the skin

  9. I think the tonsils go under-appreciated. Most times they do an awesome job of keeping harmful bacteria from finding its way into your airways and making you sick.

  10. When you lose weight, most of the fat you’ve lost doesn’t pass through stool or just “burn off”. About 90% of that weight lost is exhaled as carbon dioxide. Science!!!!!

    Also: here’s a source that’s interesting
    http://www.bbc.com/news/health-30494009

  11. You can lose up to 75% of your liver and it can grow back to its full size, kind of like how a lizard can re-grow its tail but we do it with an extremely complex organ.

    Edit: also, if you were to donate part of your liver to someone else, the piece you donated would grow into a full liver as well.

  12. We can outrun most animals in long distances due to our ability to cool, our efficient 2-legged running, etc. Over short distances, we’re boned.

  13. Mitochondria have different DNA which likely stems from the fact that they were once bacteria internalised by another single cell organism (probably archaea) very early on in the evolutionary process creating the single most important symbiotic relationship. Mitochondria are responsible for all of the energy production in your body.

  14. Look at an object on the wall across the room. Now keep looking at it while you move your head back and forth, up and down. Your eyes stay pointed at that spot. Not hard to do, is it?

    For that to happen, you brain needs to calculate the direction and rate of change your head is moving in 3 dimensional space and then send corresponding signals to the muscles in your eyes to exactly counter match the rotation and speed in order to keep them pointed at that spot. And not only that, the muscles that have to be moved (and the rate at which they move) are different for each eye, since if you turn your head quickly right, you R eye contracts the muscles on the nose side to compensate, and the L eye contracts the muscles on the temple side.

    It’s an absolutely amazing, fine-tuned process involving incredible spacial calculations and microsecond signaling and adjusting that we do all the time and take completely for granted.

  15. Our general understanding of sleep boils down to “we get tired”.

    If you mean what do we understand but most people don’t realize is extraordinary then it’s our healing ability. Compared to most other higher animals we’re basically x-men meets the terminator, we can survive and heal from things that would outright kill most animals and can chase things for days without rest.