25 Amazing Facts About the Human Body

iStock.com/kali9
iStock.com/kali9

The human body is an amazing piece of machinery—with a few weird quirks.

  1. It’s possible to brush your teeth too aggressively. Doing so can wear down enamel and make teeth sensitive to hot and cold foods.

  2. Goose bumps evolved to make our ancestors’ hair stand up, making them appear more threatening to predators.

Woman's legs with goosebumps
iStock.com/MyetEck
  1. Wisdom teeth serve no purpose. They’re left over from hundreds of thousands of years ago. As early humans’ brains grew bigger, it reduced space in the mouth, crowding out this third set of molars.

  2. Scientists aren't exactly sure why we yawn, but it may help regulate body temperature.

  3. Your fingernails don’t actually grow after you’re dead.

  4. If they were laid end to end, all of the blood vessels in the human body would encircle the Earth four times.

  5. Humans are the only animals with chins.

    An older woman's chin
    iStock.com/mhelm3011
    1. As you breathe, most of the air is going in and out of one nostril. Every few hours, the workload shifts to the other nostril.

    2. Blood makes up about 8 percent of your total body weight.

    3. The human nose can detect about 1 trillion smells.

    4. You have two kidneys, but only one is necessary to live.

    5. Belly buttons grow special hairs to catch lint.

      A woman putting her hands in a heart shape around her belly button
      iStock.com/PeopleImages
      1. The satisfying sound of cracking your knuckles comes from gas bubbles bursting in your joints.

      2. Skin is the body’s largest organ and can comprise 15 percent of a person’s total weight.

      3. Thumbs have their own pulse.

      4. Your tongue is made up of eight interwoven muscles, similar in structure to an elephant’s trunk or an octopus’s tentacle.

      5. On a genetic level, all human beings are more than 99 percent identical.

        Identical twin baby boys in striped shirts
        iStock.com/BorupFoto
        1. The foot is one of the most ticklish parts of the body.

        2. Extraocular muscles in the eye are the body’s fastest muscles. They allow both of your eyes to flick in the same direction in a single 50-millisecond movement.

        3. A surgical procedure called a selective amygdalohippocampectomy removes half of the brain’s amygdala—and with it, the patient’s sense of fear.

        4. The pineal gland, which secretes the hormone melatonin, got its name from its shape, which resembles a pine nut.

        5. Hair grows fast—about 6 inches per year. The only thing in the body that grows faster is bone marrow.

          An African-American woman drying her hair with a towel and laughing
          iStock.com/GlobalStock
          1. No one really knows what fingerprints are for, but they might help wick water away from our hands, prevent blisters, or improve touch.

          2. The heart beats more than 3 billion times in the average human lifespan.

          3. Blushing is caused by a rush of adrenaline.

22 Facts About the Solar System

Mental Floss via YouTube
Mental Floss via YouTube

So you want to know everything there is to know about the solar system? The first and most important question you might want to get out of the way is: what, exactly, isthe solar system? As Mental Floss editor-in-chief Erin McCarthy tells us, "It's a group of celestial bodies located within the Milky Way galaxy."

At the center of these bodies is the Sun, which is orbited by eight planets; more than 150 moons; and millions of meteoroids, comets, asteroids, and a handful of dwarf planets (sorry, Pluto). But it's the Sun—a.k.a. that shining, 4.5 billion-year-old star in the middle of it all—that accounts for 99 percent of the solar system's total mass. (Think about that the next time you're shading your eyes from its glare.)

In this all-new edition of The List Show, Erin is sharing nearly two dozen fascinating facts about our solar system, including the reasoning behind Pluto's demotion (blame it on Eris, the first known dwarf planet). For more out-of-this-world facts, you can watch the full episode below.

For more episodes like this one, be sure to subscribe here.

The 20 Best TV Shows on Netflix, According to Subscribers

JoJo Whilden, Netflix
JoJo Whilden, Netflix

With thousands of titles to choose from, in the time it can take a Netflix subscriber to choose what to watch next, they could be two episodes deep into a new TV series binge-watch. But as Variety reports, a recent survey conducted by HarrisX and commissioned by MoffettNathanson is helping to reduce the amount of browsing you'll need to do by going straight to the source and asking more than 11,000 Netflix subscribers to cite their favorite shows that are currently streaming on the platform. And the results were somewhat surprising.

  1. Orange is the New Black
  1. Stranger Things
  1. Movies (Catch-all category)
  1. Ozark
  1. Grace and Frankie
  1. Black Mirror
  1. Lucifer
  1. The Crown
  1. The Office
  1. Friends
  1. Dead to Me
  1. Supernatural
  1. Daredevil
  1. The Ranch
  1. House of Cards
  1. Santa Clara Diet
  1. Jessica Jones
  1. 13 Reasons Why
  1. Fuller House
  1. Breaking Bad

As Variety notes, the fact that 15 of the 20 top favorites are Netflix originals rather than licensed shows means that the company will likely continue investing in original content. This might help them out when both Friends and The Office leave the streaming service in 2020 and 2021, respectively.

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