If you're looking to be a little less conspicuous at night then your body has you covered. By the time we go to bed, we're approximately 1cm shorter than when we wake up in the morning.
Night-shrinking is a very real thing, but don't worry, it isn't permanent. Due to spinal compression (and subsequent tension) we regain the small amount of height we lose at night throughout the day. You can keep those NBA dreams alive.
Learning that there are bacteria present in our mouths won't come as a shock to most people, but the sheer amount of it might be a little shocking. Of the 615 types of bacteria in our mouths, the levels can be in the billions. Yes, billions!
These bacteria begin colonizing when we're born, some of which are good and some bad. Believe it or not, we swallow millions of bacteria when we drink a glass of water, eat some food or kiss someone, but only some of them stay and colonize.
Electrical Brain Activity
To say that your brain works hard would be the understatement of the century. Your most precious organ is constantly conducting the billions of neurons that exist throughout the body by using signals and electrical impulses.
In fact, the human brain is so hard-working that when awake, it generates approximately 12-25 watts of electricity — enough to illuminate a low-watt lightbulb. Our brain consumes glucose from our body to produce this incredible amount of energy, which is why it's so important to eat well.
Broken Heart Syndrome
You might have heard of this in books or movies, but sadly Broken Heart Syndrome is a very real condition. The actual 'breaking' of the heart is overwhelming stress on the organ itself following a traumatic event, such as a bereavement.
This stress on the heart can cause sharp pain, shortness of breath and, in severe cases, a heart attack that can lead to death. So, kids, you heard it here first, heartbreak is a real thing.
Produced by your stomach's lining, stomach acid (or gastric acid) is an incredibly important cog in the digestion process. Highly acidic, it helps to break down food, which in turn allows your body to absorb nutrients more easily.
As you can probably imagine, stomach acid is extremely powerful. Well, it is acid after all, and it could actually burn a hole in human skin. It's therefore probably best kept tucked away safely in your stomach.
Blood vessels might provide one of the most mind-boggling statistics about our amazing bodies. There are so many of them that If you were to take them out of the body and place them in a line, they'd stretch between 60,000 and 100,000 miles — that's two times the circumference of the earth!
There are actually three different kinds of blood vessels in the body: veins, arteries, and capillaries, and they all play a specific and vital role in the circulation process.
Okay, this one might freak you out slightly (but don't panic)! Around 33-50% of people have bugs, known as Demodex, living on their eyelashes. These microscopic mites can also reside in other hair follicles around the body.
The next thing you probably want to know is how do you get rid of them? Well, the cure is the same as prevention in this case: wash your face twice daily with a gentle cleanser and exfoliate once or twice a week to remove dead skin cells. It's also advisable to avoid greasy makeup.
Heart To Music Synchronization
For most of us, deciding what kind of music we want to listen to is determined by our mood at that moment. Different types of music evoke certain emotional reactions in our brains. But our music choices also affect our hearts — literally!
When we listen to a song, our heart will synchronize to the beat and beat faster or slower depending on the tempo. Looking to get the most out of a workout? Perhaps a dose of drum and bass could be the answer. Your blood vessels also contract when there's a crescendo in the music you're listening to, which could explain the meaning behind 'feeling the music'.
Enzymes In The Body
This one might creep you out a bit, so don't say you weren't warned! Our bodies naturally produce enzymes, which are proteins that help speed up metabolism and help us digest food.
Once we pass away, these same enzymes begin to feed on bodily fluids produced during the autolysis (more commonly known as self-digestion) process. Apologies if that just made you shiver!
'Get your blood pumping' is a phrase we hear used all the time when it comes to exercise and wellbeing, and for good reason. The average person's heart pumps more than 100,000 times per day, keeping the blood flowing consistently around our bodies.
When we exercise, the heart will typically pump six times faster than normal, but it can be even more, depending on the intensity of the workout. Concerned you didn't work hard enough in your last spin class? Your heart certainly did!
When a woman is pregnant, her brain gets smaller and becomes more efficient. The area that shrinks the most is the brain's grey matter, the pinkish-grey tissue containing the cell bodies and synapses of nerve cells.
The reason for this shrinkage is to prepare an expectant mother for the important task of parenthood. This incredible bodily change is, fortunately, only temporary, with the brain size returning to normal around 6 months after the mother has given birth.
Feet might not seem like the most exciting part of the body, but they are in fact a marvel of design. Together with the ankles, your feet comprise 33 joints, as well as over 100 muscles, tendons, and ligaments.
What's really fascinating about the feet, however, is that they are responsible for 25% of the bones in our bodies. Each foot has 26 bones and they are crucially important for our movement and balance and, ultimately, our survival.
Small And Large Intestines
Another incredible engineering feat of the human body is our intestines. People often confuse the two: the large intestine is larger in width but shorter in length, roughly 5 feet. On the other hand, the small intestine is far skinnier but would unravel to an impressive 20 feet long.
To put this length into context, the height of the two intestines combined would be that of a three-story building. How they pack together so neatly in our bodies is, let's face it, pretty incredible.
The Strength Of Teeth
If you were told that human teeth are just as strong as shark teeth, would you believe it? Well, you better start believing! This is mainly thanks to the enamel that covers our teeth.
Shiny and white, sure, but enamel is also 96% mineral, the highest percentage of any tissue in the human body. This durable and damage-resistant layering is even stronger than bone (although our history of fillings would beg to differ).
Baby Versus Adult Bones
Any parents reading this will relate to the notion that newborn babies seem so much softer in composition than toddlers or adults. That's because, essentially, they are. Unlike grown-ups, babies have more cartilage than bone. In fact, a baby's skeleton is mostly made up of cartilage — so be extra careful when holding your newborn nephew!
Interestingly, however, babies actually have more bones in their bodies than adults, around 305 compared to 212. This is because as a baby grows, some of those bones begin to fuse together. Pretty clever, huh?
The Weight Of Skin
A surprising fact that not many people know is that skin is our largest organ. This makes sense given how much of it there is, but do we really think of it as an organ? Isn't it just the outer layer that makes us look presentable?!
Well, now that you know that's what it is, it may also surprise you to learn that it's heavy, really heavy. Our skin amounts to just under a fifth of our total body weight.
When we think about our eyes being open or closed, we often think in very binary terms: open means we're awake, and closed means we're asleep. But that's oversimplifying things slightly.
Although blinking takes literally just a split second, we perform this act around 15-20 times every minute or 15,000-20,000 times per day. This means that our eyes are actually closed approximately 10% of the time while we're awake!
Glow In The Dark Bodies
Telling someone that they're glowing may be a compliment used when referring to the happiness they're emitting, but this would be a true statement if said to any human at any time.
Believe it or not, The human body literally glows, emitting a visible light in extremely small quantities — therefore not visible to the naked eye — at levels that rise and fall with the day. That's right folks, we're positively bioluminescent.
Black And White Dreams
Dreaming in black and white might sound like an '80s pop ballad, but it is also a scientifically proven statement about the human body. Research conducted in the 1940s concluded that around 75% of people experienced their dreams in black and white — so retro.
There is a caveat, however, as there was also a strong case for black and white television — which all TVs in the 1940s were, of course — being a strong factor in this interesting revelation. It's no surprise then, that the number of people reporting black and white dreams has fallen, although some of us still do.
The Composition Of Tears
We know that people cry for different reasons. We either weep tears of joy, tears of sadness, or... because we've been kicked in the nether regions by a soccer ball.
What's especially fascinating about tears, though, is that their composition differs depending on the type of tears we cry. These could be one of the basal tear, emotional tear, or reflex tear.
Fine Dining Syndrome
We're not joking with this one, promise! Fine Dining Syndrome, also known as 'Gourmand Syndrome' is when one becomes obsessed with fine dining.
What might appear to be simply a highly inconvenient and expensive condition, Fine Dining Syndrome is in fact a very rare and benign (cost aside) eating disorder that usually occurs 6 to 12 months after an injury to the frontal lobe.
Right, I hope you're not reading this while eating your dinner. If you are, then apologies. The heart is an incredible (and incredibly hardworking) organ, pumping around 2,000 gallons of blood around the body every single day.
To do this requires an immense amount of pressure. This pressure is so great that the heart is capable of squirting blood up to 30 feet, or half the length of a bowling lane. Impressive? You bet. Kind of gross? Correct.
The liver is a truly wondrous thing. It is the only visceral organ we possess that is capable of growing cells and regenerating. In fact, as little as 51% of the original liver mass can regenerate back to its full size.
Our livers can regenerate after either chemical injury or surgical removal, which is what it's common for a donated organ to go to more than one recipient.
This isn't intended to frighten you foodies out there, but, as we age, a number of your 10,000 or so taste buds begin to diminish, and with that, your sense of taste.
This process begins between ages 40-50, with your remaining taste buds shrinking slightly from 60 onwards. It's not all doom and gloom, however, as this process affects us to varying degrees. This is by no means an endorsement to pile on the sugar and salt!
The Length Of DNA
Human DNA has been studied — and continues to be studied — relentlessly by scientists ever since its discovery by Swiss chemist Friedrich Miescher in the 1860s.
One of the most interesting discoveries is DNA's astounding length. Comprised of coils, if you were to hypothetically unwind your DNA, it would traverse the entire solar system. Not once, but twice! That's the journey from earth to Pluto and then back again. Incredible.
Think your face is the only thing that blushes when you're embarrassed? Think again. Amazingly, the lining of your stomach follows suit, "blushing" at the same time.
The reason this happens is that the body releases adrenaline, the hormone that prepares the body for stressful situations and our capillaries widen, blood flow is increased and our stomach lining turns red. It won't typically be your stomach that gives your embarrassment away, though!
How many facial expressions can you describe? Well, there's smiling, frowning, confusion... any more? In fact, there are around 6,997 more. That's right, our incredible faces can make an extraordinary 7,000+ expressions.
Our range of facial expressions is made possible by the staggering number of muscles in our face - 80 of them in total. These expressions tend to fall under 6 key basic emotions: happiness, surprise, sadness, anger, disgust, and fear. If only there was an emoji for each of them.
Almost Indestructible Hair
It may not seem like it — especially for those of us who have experienced it falling out — but human hair is virtually indestructible. Sure, dryness, split ends, and scalp issues can affect our mane, but its resistance is legendary. Not even acids or chemicals can destroy our hair.
While this might be a pleasantly surprising revelation for you, please don't test your hair's invincibility at home! Especially with fire, which is, in fact, one of the only things that will turn your luscious locks from hair-o to zero.
This is an interesting fact and a top tip rolled into one. (You're welcome.) A fast and efficient way to relieve stress is to gently blow cold air onto your thumb. Doing this will reduce the temperature of your thumb and calm its pulse, which subsequently helps relax your entire body.
The key to this stress-busting hack is to keep your eyes closed for the duration, helping to stimulate the vagus nerve enough for it to send a message to your brain to chill out.
We often complain about our eyesight but we really shouldn't. The vision we're given by our in-built image sensors is completely unrivaled — even by the latest technology.
The naked eye is said to match a resolution of around 500 megapixels and also has the ability to scan 180 degrees. Incredibly complex in design, human eyes have over 100 million rods and over 5 million cones. Nonetheless, having to put in contact lenses every morning is still a bit of a pain.
New Skeleton Every 10 Years
That's right, we humans essentially have a new skeleton every ten years. Now, we don't discard our old ones like a snake sheds its skin. Rather, our body is constantly regenerating bone, slowly upgrading from within.
The process of a body's skeleton forming and growing to its adult size is called modeling. When it regenerates and replaces old pieces of bone with fresh new bone tissue this is known as remodeling. Now you've got something to talk about when you put on your favorite Halloween costume!
The human heart is such an incredibly powerful, autonomous organ that it can carry on beating even when removed from the body. It will actually keep on beating for as long as it has oxygen.
We know what you're thinking: how? The heart actually has its own electrical system that allows it to beat and pump blood around our bodies. So are we in control of our heart, or is our heart in control of us? Perhaps this explains some of our questionable romantic decisions.
No, we're not talking about the inflammation of the transparent membrane that lines your eyelid and eyeball (otherwise known as conjunctivitis). Rather, we're referring to the little pink area in the inner corner of the eye.
Long ago, this little pink triangle was actually an inner eyelid, similar to what you see in reptiles and birds. But over time, the evolution of the body decided that this wasn't necessary and diminished, leaving us with this little section we're so familiar with today.
We're sure no one wants to hear this, but as we get older we also get shorter. Yes, once we've reached our peak height — around the age of 30 — we begin a slow shrinking process.
Fear not, though. This isn't drastically noticeable, we're talking approximately half an inch every ten years. So if you're strapping 6 foot 2 inches at the age of 30, you'll still be an impressive 6 foot and a half aged 60.
It sounds terrifying, but exploding head syndrome (EHS) isn't painful. It's where you hear a loud noise, like a bomb exploding, right before you fall asleep or wake up — a noise that other people don't hear.
EHS affects around 10% of the world's population, so it's far more common than we realize. Why do they experience it? Researchers still aren't entirely sure, although the likely causes are stress or anxiety, sudden shifts in the parts of the middle ear, or even minor seizures in the temporal lobe of the brain.
This might sound like an outlandish statement, but we as a species are technically more bacteria than we are human. Creepy, huh? This is because there are about 10 times as many microbial cells in the human body as there are human cells.
Depending on how the bacteria inside us behave, it can have a huge impact on our health. Many disease-causing bacteria produce toxins, which are powerful chemicals that damage cells and make us ill. Other bacteria can directly invade and damage tissues, wreaking all kinds of havoc.
Why are kidneys so important? They are tasked with filtering our blood as often as 25 times per day. The human body contains a huge amount of blood, somewhere between 7 and 8 liters, and it's crucial for our health that this blood is filtered.
Each of our kidneys is made up of around a million filtering units called nephrons, which include a filter (called the glomerulus) and a tubule. These nephrons work through a two-step process: the glomerulus filters blood while the tubule returns essential substances to the blood and removes waste. Impressive stuff!
The key to preventing — or reversing — a cavity is practicing good oral hygiene. Daily brushing and flossing, exposure to fluoride, and regular cleanings can ultimately be the difference between a nice set of healthy teeth and a painful bout of tooth decay.
What you probably didn't know, however, is that kissing is nature's natural cleansing process. According to the Academy of General Dentistry, kissing stimulates saliva, which washes out the mouth and helps remove the food particles that accumulate after eating and cause cavities. So there you have it, an excuse for a smooch!
The space enthusiasts amongst you might already know this, but if not, you're in for a starry-eyed surprise. The human body contains approximately 97% of the same atoms found in our galaxy, and the elements of life appear to be more prevalent towards the galaxy's center.
This astonishing discovery means that around 93% of our body mass is, technically, stardust. In fact, nearly half of the atoms that make up our bodies may have formed beyond the Milky Way and traveled to the solar system on intergalactic winds driven by enormous exploding stars. Quite literally out of this world!
Apologies for the slightly disgusting title, but our body's spit production is an essential mechanism. To keep our mouth moisturized and assist with digestion, the average mouth will produce between 1 and 2 liters of saliva every day. That's a whole load of spit.
Our brains can help with this production just by thinking about food (preferably something delicious), so the next time you're accused of salivating over the dessert menu, you can politely explain to your fellow diners that you're simply promoting an essential bodily function.
Although we're not natural inhabitants of the water, our body does us an incredible favor when we submerge. Essentially, our systems shut down to preserve energy — a phenomenon known as the 'Diving Reflex'.
The way our bodies know to kick into this reflex is upon wetness of the face and nose. This happening causes bradycardia, apnea, and increased peripheral vascular resistance, the three main physiologic changes that, collectively, define the Diving Reflex. We wonder if this works in the shower? Only one way to find out.
Humans typically have a complicated relationship with body fat. For most of us, it's a source of frustration and something we're always trying to eliminate by dieting and/or working out.
However, body fat plays an extremely important role for us as a source of stored energy that's used for daily activities and to maintain body functions. Shockingly, did you know the average person has enough fat stored in their body to make 10 — yes 10 — bars of soap?
Cornea Of The Eye
The cornea is the transparent part of the eye that covers the front portion and its main function is to refract, or bend, light. The cornea is somewhat unique in that — unlike most parts of the body — it doesn't have its own blood supply. Instead, it relies on oxygen from the air it's exposed to.
The cornea may contain no blood vessels, but it does contain many nerves and is therefore super sensitive to pain or touch. So, ideally, try to not get poked in the eye too often. You're welcome!
Have you ever wondered when we develop our fingerprints? It's fascinating. They begin appearing during the phases of fetal development, around the 17th week of pregnancy, and continue developing and transforming as the baby does.
The unique pattern of our fingerprints — the arches, whirls, loops, and bridges — are fully formed by the time we're born. So in theory, a newborn baby would be able to unlock an iPhone. (Don't worry, we haven't tested this.)
Like many facts about the human body, embryo development is both fascinating and... pretty funny. The first part of the future body to develop in a human embryo is the anus. Followed by the mouth.
When do we switch from embryo to fetus you ask? Well, a developing human is referred to as an embryo for the 6 weeks from weeks 3—8, and a fetus from the ninth week of gestation all the way through to birth.
Okay, we think we have a new challenger for the most terrifying title on the list. This sounds straight-up scary but be warned, this can genuinely happen when someone embarks on an extreme diet.
The cells in the brain — starved of required energy sources — begin to consume small portions of themselves. But it gets worse. The brain will also begin to eat itself after chronic sleep deprivation. Right, we're off to bed via the fridge!
As if aspiring astronauts needed any more convincing that journeying into space is an experience like no other, it turns out there's an unexpected bonus in the job as well.
Upon returning to earth, astronauts will find themselves slightly taller than when they took off for space. This is due to the direct impact gravity has on the human body. So if you've always wanted a few more inches you'd do worse than to call NASA.
The human body is like that sensible person who backs up their work on an external hard drive, and it's been proven to save the day (literally!) on many occasions.
Where our body has two of the same organ, it can actually survive with just one of them. Puncture a lung? No problem. Lose a kidney? We're all good.
Lack Of Oxygen In The Brain
There is a common misconception that a lack of oxygen to the brain means certain, sudden death. Fortunately for us, this isn't quite the case.
In fact, we can survive an incredible 5 to 10 minutes without oxygen to our brain. This is why CPR places more focus on chest compression rather than mouth-to-mouth resuscitation.
Swallowing And Breathing
Now, let's have a little fun, shall we? Grab a glass of water and try to swallow and breathe at the same time. Are you still trying? Don't bother, it's physically impossible!
This is because breathing ceases briefly during swallowing, due to inhibition of respiration at neural control centers in the brainstem. Fun fact, right?
There are few things in life more devastating than being diagnosed with cancer or witnessing a loved one receive the diagnosis. However, our amazing bodies are fighting night and day on our behalf to prevent the unthinkable from happening.
The cells in our bodies are constantly dividing and making repairs to ward off harmful intruders, so there's actually a good chance you've fought off cancer before without even realizing it.
Size Of The Brain
People make all sorts of rude remarks about the size of peoples' brains (usually between friends), but as humans, we all boast this incredible organ, that is now more advanced than anything comparable in the history of the natural world.
However, considering the relatively modest size of our heads, it's incredible that our most precious body part even fits inside! In fact, the brain is so big, that if flattened (yuck!) it would cover an entire pillowcase.
The kidneys are a fascinating organ, but one that most of us probably know little about - until we have to, that is. Their primary role is to cleanse the body's blood of toxins and transform the waste into urine.
The kidneys may be virtually identical in appearance, but the one on the left side of our body sits higher than the one on our right. Thankfully, it's also possible to live a healthy and active life with only one functioning kidney.
If you've ever wondered why we blink, it's a process that our body does automatically to generate fluid that lubricates our eyes and thus preventing them from drying out. If you've ever suffered from chronic dry eyes or blepharitis, you'll know how important blinking is!
What's interesting is the rate at which humans do it — on average, adults blink around 10-15 times every minute. Newborns and infants, however, blink far less often — only a handful of times every minute, with some babies blinking as little as once a minute!
We're all familiar with fingerprints — whether it's from true crime documentaries or airport security, our unique fingerprint is a well-known source of identification. What you might not have known is that everybody has a unique tongue print as well.
Plenty of research has been done on using tongue prints as a biometric authentication tool and these studies have found it to be beneficial and comparable to other biometric tools. So, get ready to present your tongue when catching a flight in the future.
The Strongest Muscle In The Body
Here's a useful fact just in case you end up on Who Wants to Be a Millionaire. The strongest muscle in your body is the masseter, the muscle which runs through the rear part of the cheek from the temporal bone to the lower jaw on each side and closes the jaw when chewing.
The masseter truly punches above its weight, capable of closing the teeth with a force as great as 55lb on the incisors and 200lb on the molars. That's some serious biting power!
Shedding Skin Cells
Shedding skin cells may only be obvious after your vacation tan (or sunburn!) is healing, but it's actually an everyday occurrence. Humans shed their entire outer layer of skin every 2-4 weeks, or if you prefer, 0.001-0.003 ounces of skin flakes every hour.
An average night of sleep can yield over 12 million — yes, million! — dead skin flakes, which eventually end up in your mattress much to the delight of dust mites. Buying a new mattress doesn't seem so pointless now, right?
Running A Temperature
In response to an illness or infection, the hypothalamus — the part of our brain that controls our body temperature — might reset the body to a higher temperature. When this happens, it's a sign there's something untoward happening in our bodies.
Running a temperature is concerning, but we usually know how to deal with it. However, a seriously higher temperature, above 104, can shut down your body's organs. The highest temperature ever recorded was 115, but thankfully the person survived.
Ready for some dental tips? Many people think that when brushing their teeth, the more vigorous the better. In fact, scrubbing your teeth aggressively can actually cause damage by removing the all-important enamel that keeps your teeth strong.
Instead, brushing your teeth for longer in a more gentle manner is the optimal way to clean. It's also important to devote time to the "hard to reach" areas, which can become problematic if not tended to.
Right- Versus Left-Handed
Now, don't panic if you're left-handed! But... several studies (albeit controversial ones) have found that right-handed people live longer than their left-handed counterparts.
The discrepancy in lifespan was particularly eyebrow-raising — according to the studies, a right-hander lives on average an extra 9 years. However, there was found to be a major error in these findings, which was looking at data from throughout the 20th century. Left-handed? Don't worry about it!