The human body is an intricate piece of machinery capable of performing incredible tasks. Every day, with the coordination of our sensory organs as well as our limbs, we are able to do things that no other living being can. While we are different and on top of the food chain, there are countless incredible things we didn’t know about our own body. Here are 21 amazing facts about the human body that are sure to surprise you.
1. The cornea is the only part of the body with no blood supply. It gets its oxygen directly from the air.
It’s true that the cornea is the only part of your own body that receives its oxygen directly from the air. It is also the fastest healing tissue in the human body.
2. There are more bacteria in your mouth than the entire population of Earth.
It’s no secret that our mouths are a safe haven for micropests to dwell. It is estimated that there are about 20 billion bacteria thriving within the confinements of our mouths and they multiply every five hours. So, if someone does not brush for 24 hours, those 20 billion become 100 billion!
3. We’re as hairy per square inch as chimpanzees.
It’s a known fact that us humans have a lot of similarities with chimpanzees. And it turns out, we are just as hairy as them; according to a 2011 paper published in the International Journal of Trichology. The hair is much finer on us humans, making them harder to see and creating a lower volume of hair overall.
4. Hair can “taste.”
The nasal passages and the lungs in our bodies are lined with fine hairs, or cilia, whose official duties are to detect and sweep out impurities. So, how do they detect it? By tasting the things passing through them and detecting bitterness. So, when these hair follicles detect something bitter, they immediately start moving at an increased rate, like sort of sweeping the impurities out.
5. Your hair also knows when you are sleeping.
Have you ever woken up feeling exhausted and someone looked at you and said “You look like you had a rough night?” Well, this is because your hair shows when you have slept good or had a rough night. A 2010 study conducted by researchers at Yamaguchi University found that “hair follicles contain a signature of the 24-hour circadian clock that sets our sleeping habits.” The cell-rich hair follicles contain RNA from “clock genes” that express each person’s sleep-wake cycle, capable of showing your sleep patters.
6. Your nails grow faster today than they used to.
Have you ever felt like your nails grow extremely fast, even though you just trimmed it a few days ago? If you have, then you are not imagining things. A 2010 study out of the University of North Carolina focused on the growth of fingernails and toenails to two previous studies from 70 and 50 years earlier and discovered that their growth had increased by almost a quarter over the decades.
7. Between the age of 1 to 100, you go from having 300 bones, to just 206.
It’s true! When we were young, we had more bones in our bodies than we do now. When we were born, we were born with around 90-95 extra bones or around 300 bones. A grown adult at the same time has 206 bones.
8. Humans are bioluminescent, but the light just isn’t perceptible to the human eye.
Japanese scientists, with the help of some ultra-sensitive cameras were able to discover that humans are bioluminescent. In fact, it was known that all living creatures emit a small amount of light but this is the first time scientists have been able to capture the light produced by humans. The research also found that the amount of light emitted follows a 24-hour cycle, at its highest in late afternoon and lowest late at night, and that the brightest light is emitted from the cheeks, forehead and neck.
9. A blink is a micronap.
One would assume that blinking is the process of keeping our eyes lubricated or preventing dust particles from reaching them. While those are some of the processes that happen while we blink, the real reason is to sharpen our attention and provide our bodies with enough time to recharge; according to a 2013 study conducted by researchers at Washington University.
10. Your gut has a “second brain.”
The “butterflies in the stomach” sensation is something we have all felt at least once in our lifetime. This feeling often appears when we are making important decisions of when we are alone in an unfamiliar place. There’s a good reason for this. Scientists describe that our gut is not just used for digestive purposes but to also make decisions. The intricate system is connected to our nervous system, and is capable of operating independently of the brain and spinal cord. So yes, if you ever get that feeling that something is wrong, trust your gut!
11. Our taste buds grow with us and as we age. They become dull.
Your sense of smell and taste are connected and as we age, these senses can change, causing certain foods to not be as flavorful as they used to be. As we get older, the taste buds regenerate more slowly, causing a steady decline with the sense. Studies show that women start experiencing taste sensitivity beginning in their 50’s, while men don’t experience that until their 60’s.
12. The speed of an incoming brain impulse is about 268 miles/hour.
Have you ever wondered how fast the nerves send signals to and from the brain? Or how fast our thought process is? While it’s complicated and different among individuals, scientists discovered that on an average human being, messages in the brain can travel at speeds up to 268 miles/hour.
13. A human makes approximately 20,000 breaths per day.
Whether you’re awake or asleep, your lungs have a full-time job to keep you alive. So, on average, a human takes about 20,000 or so breaths per day. By the time you’re 50, you have taken around 400 million breaths.
14. Almost all people in the world have special mites on their eyelashes called demodex.
While there’s no reason to freak out, you almost certainly have tiny mites living in the pores of your face right now. Known as Demodex or eyelash mites, just about every adult on Earth has a decent amount living on them. Although they are not visible with the naked eye, the eight-legged creatures like spiders are certainly there. According to the BBC, they spend their entire lives on our faces and almost entirely harmless.
15. A human eye is capable of distinguishing around a million different colors.
A human eye has three types of cone cells, each of which can register about 100 different color shades. Therefore, most researchers estimate that the number of colors we can distinguish is around a million. There are however some people, who are tetrachromats. Their eyes possess a 4th type of cone which expands their vision by an estimated 100 times, giving them the ability to distinguish 100 million colors.
16. 1 square centimeter of your skin contains around 200 pain receptors.
According to the BBC, every square centimeter of your skin contains around 200 pain receptors but only 15 receptors for pressure, 6 for cold and 1 for warmth.
17. The average person consumes about 35 tons of food during his or her life.
The average person eats about 35 tons of food during a lifetime or 1,500 pounds of food a year.
18. Every second, 100,000 chemical reactions take place in our brains.
The human brain is probably the most complex entity known to man since more than 100,000 chemical reactions occur per second. Your brain also uses 20% of the total oxygen in your body.
19. Smiling helps you live longer. So smile more often.
The study in Proceedings of the National Academy of Sciences found that people who had higher levels of optimism had a longer life span. They also had a greater chance of living past age 85.
20. Your hair is so strong that a single strand could hold the weight of a hanging apple.
More than 150,000 strands of hair is grown on an average person’s head and the average strand has a lifespan of about 4 years. In fact, each strand of hair on your head is so strong that scientists say it is capable of holding 100g (3oz) in weight; or an apple. The combined hair of a whole head could support 12 tons, or the weight of two elephants.
21. Your body position affects your memory.
There’s a reason why experts recommend that you maintain a proper posture while working. A 2012 article published in Biofeedback found that sitting and looking downward makes it easier to recall negative memories, while sitting upright and looking upward makes it easier to recall positive, empowering memories.