20+ Mysteries About the Human Body You’ve Never Even Thought About

By molly atherton 4 months ago
Despite the strides in medical science and our ever-growing understanding of anatomy and physiology, there remain enigmatic aspects of our bodies that continue to baffle even the most seasoned experts. From the complexities of the brain to the mysteries hidden within our cells, there is a plethora of questions that have yet to find concrete answers. In this journey, we invite you to delve into the astonishing and often perplexing mysteries that lie beneath the surface of our very existence.

You'll have a new skeleton in 10 years

Over the course of roughly 10 years, this regenerative process results in a complete turnover of our bone mass. This means that the skeleton you have today is not the same one you had a decade ago. This renewal not only helps maintain the strength and integrity of our bones but also allows our bodies to adapt to various environmental factors, lifestyle changes, and even injuries.

Image Source: Reddit

Did you know that you will have a brand new skeleton every 10 years? This is because the cells in the skeletal system are always regenerating and so in roughly 10 years time, you will have a completely new set of bones inside your body…pretty cool right?

Half of the strength in your hand comes from your pinkie finger

The biomechanics of hand function reveal that the pinkie is not merely a passive bystander; rather, it actively supports the thumb in crucial pinching motions. This collaboration between the thumb and pinkie is essential for tasks that require precision and a firm grip, such as picking up small objects or manipulating tools.

Image Source: Reddit

I bet you wouldn’t assume that half of your hand strength would come from your smallest finger! You’re probably wondering how this is possible, but it turns out that the pinkie helps the thumb to pinch and supports your other three fingers to give more power.

You can’t tickle yourself

When you try to tickle yourself, your brain predicts the exact nature and timing of the sensation based on the motor commands it sends to initiate the movement. This predictive process helps in distinguishing self-induced sensations from those caused by external factors.

Image Source: Smithsonian Magazine

Have you ever noticed that you can tickle other people, but have you ever tried to tickle yourself…well you can’t because it is physically impossible! Your brain predicts the sensation we would feel if you tried to tickle yourself and so it counteracts the response.

Humans are just as hairy as chimpanzees

In essence, the seemingly disparate levels of hairiness between the two species are not a result of a significant variance in hair density but rather a consequence of the finer and less conspicuous nature of human hair.

Image Source: Reddit

Although from the outside you would probably assume that chimpanzees must be more hairy than humans just by looking at them, research has proven that they both have just as many hairs. The difference is humans have finer hair which make it harder to see, creating the illusion that they are not as hairy.

Babies aren’t born with kneecaps

The development of knee caps is a testament to the intricacy of human physiology and the coordinated dance of genetic instructions guiding the growth and maturation of the skeletal system. This process is not an overnight phenomenon but rather a gradual journey that extends into the years of adolescence.

Image Source: Reddit

You might be wondering how this can be possible, but it turns out that you were not actually born with knee caps just cartilage which slowly turns into bone as humans reach the age of 2 to 6 years old. This process continues and knee caps aren’t fully developed until early adulthood.

Everyone has a unique tongue print

The uniqueness of the tongue print lies in the myriad of factors contributing to its individuality. The shape, size, and surface texture of the tongue, along with its sublingual veins and papillae, all contribute to the creation of a distinct and personal identifier.

Image Source: Reddit

We all know that humans have a unique fingerprint, but did you know they also have a unique tongue print? Research studies have compared the shape and texture of individual tongues using a special mapping device which has revealed not one of us has the same tongue.

Human bones are stronger than steel

The strength of bones is primarily attributed to their unique composition, which combines a rigid mineral matrix, mainly hydroxyapatite crystals, with a flexible protein matrix, predominantly collagen. This amalgamation creates a material that is both sturdy and resilient.

Image Source: Reddit

You’re probably wondering how human bones could possibly be stronger than steel…well, this amazing mystery is actually true when you compare the pressure tolerance and strength of a rod a steel compared to a human bone with the same width. Unfortunately this doesn’t stop humans breaking them!

Stomach acid can dissolve metal

The fascinating research findings highlight the remarkable and potent nature of human stomach acid, unveiling its ability to dissolve metal objects. The implications of such a discovery extend beyond mere curiosity, presenting potential applications in the realm of medicine and toxicology. Understanding the corrosive capabilities of stomach acid could inspire innovative approaches to the removal of ingested foreign bodies or the development of targeted treatments for certain conditions.

Image Source: Freepik

Research has shown that human stomach acid can actually dissolve metal objects. They trialled this using metal razor blades over a period of 24 hours and the weight of the blades were reduced by 63%, so you’d probably have a good chance of getting rid of anything unwanted inside of you!

Humans are the only species that cry

While various animals do generate tears, their primary function is limited to serving as a lubricant to maintain moisture in their eyes. In stark contrast, humans uniquely exhibit the phenomenon of shedding tears not just as a physiological necessity but also as a profound emotional response.

Image Source: Reddit

Although other animals do produce tears, this is only for the purpose of being a lubricant to keep their eyes moist. Humans are the only species who produce tears as an emotional response which serves as a social purpose to express feelings to others.

Your tongue is the only muscle in the body only connected to one bone

The intricate design of the human body showcases a fascinating interplay of muscles and bones that enables a wide range of movements. In the majority of cases, muscles are connected to two bones at each end, forming a system that facilitates contraction and relaxation, thereby allowing the body to perform various actions.

Image Source: ResearchGate

Every muscle in the human body is connected to two bones at each end which allows it to pull and create movement by contracting and relaxing. But there is one exception…your tongue is only connected to the hyoid bone at one end and nothing else on the other side.

Having dirty hair helps the environment

It's almost as if your hair acts as a natural shield, trapping these pollutants and preventing them from making direct contact with your scalp. Now, let's talk about scalp oils — the unsung heroes in this intriguing story.

Image Source: Reddit

You’re probably wondering how this is even possible…well, science has proven that hair absorbs air pollutants and scalp oils are a big contributor to this process. So, the less you wash your hair, the more scalp oil you will retain and the more pollution will be absorbed!

The smallest bone in the human body is in your ear

When sound waves reach the ear, the stapes vibrates in response, setting in motion a chain of events that culminate in the conversion of these vibrations into electrical signals interpreted by the brain.

Image Source: Reddit

The human body contains over 200 bones, but you’ll be surprised to hear that the smallest bone can be found in your ear. The stapes is a tiny stirrup-shaped bone located in the middle ear and it is responsible for transmitting sound waves from the outside air to the cochlea.

The human intestine is 4x as long as you are

The significance of this design becomes apparent when considering the small intestine's vital role in the digestive process. Its lengthy structure provides an extensive surface area for nutrient absorption, a crucial function for sustaining the body's energy and overall well-being.

Image Source: Freepik

You’re probably thinking, surely this can’t fact be possible? But it turns out the small intestine can be anywhere from 18 to 23 feet long depending on the size of the person, but it is coiled up tightly which makes it able to fit inside the human body.

You’re taller in the morning than you are at night

Throughout the day, this compression causes the cartilage to lose some of its fluid content, leading to a subtle reduction in the overall height of the spine. However, during the night, when we lie down to rest, the pressure on the spine is alleviated.

Image Source: Daily Yogi

We promise this one isn’t a myth, it is a true fact! We are all a tiny bit taller when we wake up first thing in the morning compared to when we go to bed at night because of the pressure put on our joints throughout the day which compresses the cartilage in our spine.

Sneezes can travel as far as 20 feet

The human sneeze, it appears, is a force to be reckoned with, showcasing an impressive ability to disperse microscopic droplets across considerable distances. This revelation challenges conventional notions of personal space and raises awareness about the potential transmission of respiratory particles even in seemingly distant settings.

Image Source: MyLondon

You’d probably only think a sneeze would reach you if you were in close proximity to the person who produced it in the first place, but research has proven that they can travel much further than we would think…a video study has shown they can travel up to 20 feet!

A quarter of your bones are in your feet

The muscles in our feet, with their finely tuned coordination, allow us to navigate various terrains, adapt to different surfaces, and maintain balance with an impressive degree of precision.

Image Source: Reddit

As we mentioned previously, the human body contains over 200 bones but would you believe that a quarter of them can be found in your feet? Each foot contains 26 bones which makes a total of 52 bones! They also contain over 100 muscles, tendons and ligaments.

Your hair knows your sleeping pattern

Picture this: your hair, a biological archive, could be analyzed to reveal patterns, irregularities, and even subtle shifts in your sleep-wake cycle. This information could be a valuable tool for both medical professionals and individuals seeking to optimize their sleep routines.

Image Source: Reddit

I bet you weren’t expecting to find this one out…the hair on your head can actually track your sleeping pattern! They can do this because our hair follicles contain ribonucleic acid (RNA) from ‘clock genes’ which express each humans sleep-wake cycle.

There are no muscles in your fingers

Instead of relying on muscles embedded within the fingers, the grace and agility of finger movements primarily stem from the coordinated efforts of bones and tendons. Picture the fingers as a complex ensemble, with the bones forming a structural framework and the tendons acting as the pulleys that connect muscles from the palms to the fingertips.

Image Source: Reddit

Because human fingers are responsible for some many important fine motor movements, you’ll be surprised to find out that they don’t actually contain any muscles. Any motion is purely down to bones and tendons with some help from muscles in the palms of your hands.

You lose a third of your bones as you get older

As the human body embarks on its incredible odyssey of growth, a transformative process called ossification takes center stage. Ossification, often likened to the gradual sculpting of a masterpiece, involves the fusion of certain bones over time.

Image Source: Essex TV

Although the average adult has over 200 bones in the human body, you are actually born with nearly 300 bones! As humans grow, some of these bones fuse together through the process of ossification which leaves you with about 206 bones by the time you reach adulthood.

The largest muscle in your body is the gluteus maximus

Beyond its mechanical significance, the gluteus maximus has garnered attention for its role in maintaining posture and contributing to overall spinal stability. When activated, it helps stabilize the pelvis and supports the spine, playing a crucial role in preventing lower back pain and injuries.

Image Source: Reddit

Although the gluteus maximus is not technically the strongest muscle in your body, it is certainly the largest! This important muscle is the outermost of three gluteal muscles that make up the human buttocks and it is the main extensor muscle of the hip.

The hairs in your nose and lungs can ‘taste’ things

These specialized hairs act as sensory receptors, capable of discerning the presence of noxious particles, pollutants, and irritants in the air you inhale. When cilia come into contact with these undesirable elements, they trigger a response that sets off a coordinated and rhythmic sweeping motion.

Image Source: Reddit

Have you ever wondered how the fine hairs which line your nose and lungs are able to detect and remove impurities? These hairs are called ‘cilia’ and they do this by important job by sensing the bitter taste of bad substances and sweeping them out of our body.

Your nails will grow more quickly today than they did yesterday

A key insight into this phenomenon can be found in the evolving dietary habits of the human population. Researchers have meticulously studied the correlation between nail growth and dietary patterns, and a compelling connection has emerged.

Image Source: Reddit

You’re probably wondering, how is this possible? Well, it turns out that nails are growing more quickly than ever before and the rates have increased by 25% over the last few decades. Researches have attributed this to the fact that humans now eat more protein-rich diets.

The human liver can grow back to its normal size if it gets damaged

The regenerative process unfolds with precision, driven by the activation of signaling pathways that prompt cell division and proliferation. As hepatocytes divide, they seamlessly replace damaged or lost cells, gradually restoring the liver to its original form and functionality.

Image Source: Freepik

The liver is one of the most resilient organs in the human body and research has shown that it has the ability to completely regrow back to its original size if it was damaged by up to 75%. This is possible because liver cells replicate at a very fast pace.

Having a bad posture can affect your memory

When we talk about posture, we're not just referring to the way we sit or stand; it extends to the overall alignment and positioning of our body. The impact of posture on memory recall can be attributed to the intricate interplay between our nervous system, hormonal balance, and cognitive functions.

Image Source: Reddit

If you’re wondering what your posture has to do with your memory, we have the answer! According to research, having a bad posture makes it easier to recall negative memories whereas having a good posture can actually makes it easier to recall positive memories.

The bigger your eyes, the worse your eyesight could be

The eye functions like a sophisticated optical system, wherein light is refracted and focused onto the retina at the back of the eye. In the case of myopia, the eyeball is often longer than usual, causing the focal point of light to fall in front of the retina rather than directly on it.

Image Source: Reddit

It would make logical sense to assume that the bigger your eyes, the better your eyesight would be…but this is not the case. Having big eyes can actually make it more likely to have a condition called myopia which means distant objects look very blurry.

The human body glows but you can’t see it

The phenomenon of the human body emitting visible light, though imperceptible to the naked eye, adds a fascinating layer to our understanding of the human form. When someone remarks that you have a "glow" about you, they might be unknowingly tapping into a scientific reality that extends beyond mere metaphor.

Image Source: Pinterest

Has someone ever said you have a “glow” about you? Well, it turns out the human body actually does emit visible light but you can’t physically see it because it is approximately 1,000 times less intense than the levels to which the human eye is sensitive to.

Blinking is the equivalent of having a mini nap

Every time you blink, your eyelids momentarily shield your eyes from the surrounding environment. This brief interruption in visual input allows your brain to divert its focus from external stimuli, providing a micro-moment of rest.

Image Source: Exclusively Eyecare

Humans blink so often that you probably wouldn’t think anything of it. But it turns out that blinking is actually more important than just protecting our eyes and keeping them moist, it actually gives your body time to recharge and improves your attention skills.

Your tastebuds get less sensitive as you get older

Interestingly, this age-related decline in taste sensitivity is not uniform across genders. Research suggests that females tend to encounter these changes earlier than their male counterparts. The reasons behind this discrepancy are multifaceted and can be influenced by a combination of genetic, hormonal, and environmental factors.

Image Source: Reddit

Vision and hearing are not the only senses which start to deteriorate as your get older….your tastebuds also start to dampen and become less sensitive because the cells regenerate more slowly with age. Females are more likely to experience this earlier than males.

Our stomach has its own brain

What's truly intriguing is that the enteric nervous system is closely interconnected with the central nervous system, which includes the brain and spinal cord. The two systems communicate bidirectionally through an extensive network of nerves, hormones, and neurotransmitters.

Image Source: Pinterest

Have you ever wondered how your stomach is closely linked to your emotions, for example you feel nervous 'butterflies' in your stomach before a momentous occasion. Well, it turns out that our gut is lined with a network of neurons linked to our main nervous system!

Humans have more than five senses

We’ve all heard the term of having a ‘sixth sense’ but this term is scientifically incorrect because humans have more than five senses anyway! Alongside vision, smell, hearing, touch and taste, humans also have something called ‘nociception’ which is the sense of pain and up to 27 others.
Image Source: Today I Found Out

One such sense is nociception, which refers to our capacity to perceive pain. This sense plays a crucial role in alerting us to potential harm and ensuring our survival. Beyond nociception, researchers have identified numerous other senses that contribute to our perception of the world around us.

The whole of our skin is replaced each month

Contemplating the idea that in just one month, our bodies undergo a remarkable transformation, resulting in an entirely new layer of skin, is indeed a fascinating and somewhat surreal notion. The intricate and continuous process of cell turnover ensures that our outermost protective barrier, the skin, is in a constant state of renewal.
Image source/ Reddit
It's a very strange thought to think that next month, we will have an entirely new skin. Our cells are shedding and replacing so often that it only takes around a month for all of the skin cells to have been replaced by entirely new ones. Meaning in an average life we have around 1,000 completely new skins!

Each minute we shed around 30,000 dead skin cells

So, where does all this accumulated debris go? It settles on surfaces, creating the familiar layer of dust that coats shelves, tables, and corners. Dust bunnies lurking under furniture and on top of cabinets are, in essence, miniature mausoleums for the remnants of our skin's past.
Image source/ Reddit
This sounds cool until you realise where those skin cells are going. So if you've ever wondered where all the dust in your house comes from and why you have to hoover so often - here's the answer. The majority of dust is our dead skin. Pretty gross right?

Your appendix hasn't lost its function after all!

Contrary to the common misconception that appendixes are vestigial organs with no significant purpose, recent scientific research has shed light on their potential importance in maintaining a healthy digestive system.
Image source/ Reddit
The thing we tend to know about appendixes is that they lost their use a LONG time ago and now they're in our bodies occasionally getting infected and causing appendicitis before having to be removed. Wrong. They are actually important in maintaining healthy gut bacteria.

Females contain way more DNA than males

The disparity in the size and complexity of the X and Y chromosomes translates to a significant distinction in the overall genetic content between males and females. In essence, women possess a greater abundance of genetic material, often referred to as 'information,' owing to the presence of two expansive and intricate X chromosomes.
Image source/ geneticliteracy
Females contain two X chromosomes, whereas males only contain one X, along with a Y chromosome. But the X chromones carry a lot more DNA in them than Y. They are much more complex. This means that women contain a lot more DNA or 'information' than males do.

You blink around 20 times a minute

Delving deeper into the numbers, the average person blinks around 20 times per minute, which accumulates to a staggering 1,200 times per hour. Over the course of a day, this amounts to a remarkable 28,800 blinks.
Image source/ Reddit
That is a serious amount of blinking, and it equates to blinking once every 3 seconds which sounds like a lot but on average this is correct. That is the equivalent of over 10 million times a year! So essentially, we spend a lot of time with our eyes closed...

The tongue is covered in around 8,000 taste buds

Whether it's the subtle sweetness of a ripe fruit, the savory richness of a well-seasoned dish, or the fiery kick of a spicy creation, our taste buds are the unsung heroes that transform mere ingredients into a sensory masterpiece.
Image source/ Reddit
Think about when you taste something salty or spicy and your tastebuds go into overdrive. This is why, because we have 8,000 taste buds helping us taste our food and allowing us to try our culinary delights. These taste buds are each made up of around 200 cells.

Goosebumps are a feature of our ancestral past

Humans, despite lacking a dense fur coat, still retain this instinctive response. When we experience fear or extreme emotions, the arrector pili muscles contract, causing goosebumps. This is a physiological echo of our ancestral past, a reminder of the times when our survival depended on our ability to convey strength and resilience in the face of danger.
Image source/ CBC
Have you ever wondered why we get goosebumps? Of course there's the reason of fluffing up our fur to trap in heat when we are cold. But goosebumps can also be produced by a motion. When animals get scared they fluff up their hair to look more threatening. We still do this, without the excessive fur.

On average, we produce a cupful of 'snot' a day

Consider the unsuspecting nose – an organ often overlooked in its intricate workings. No longer will you view this facial feature through the same lens. Every nose becomes a factory, quietly and consistently producing a daily quota of mucus that, until now, may have gone unnoticed in the grand scheme of bodily functions.
Image source/ Reddit
Here's a fact that you definitely did not need to know, and probably wish you didn't now. Because now you do, you can probably never forget this. A cupful of nasal mucus is produced on average daily. You'll never be able to look at a nose in the same way again.

The only muscle that never gets tired is your heart

Gratitude is owed to the heart's relentless commitment, for it diligently undertakes its vital role without respite. With each pulsation, it propels life-sustaining blood throughout the vast network of arteries and veins, ensuring the delivery of oxygen and nutrients to every corner of our body.
Image source/ Reddit
The only muscle in our entire body to never ever tire is our heart. And thank goodness it does not, our heart is working constantly each second, every day for the entirety of our lives. No other muscle can continue without the proper rest and recovery!

The body has 2.5 millions sweat pores

Sweating is a remarkably efficient and essential mechanism for maintaining our internal balance. As we engage in physical activities, heat is generated within our muscles, prompting the body to initiate the cooling process through perspiration. This natural cooling system involves the secretion of a saline solution through the sweat glands, which then evaporates on the skin's surface, effectively dissipating excess heat.
Image source/ Reddit
Think about this one next time you're doing a workout and wondering why you are sweating so much. We are covered in 2.5 million sweat pores which basically allows sweat to ooze out from pretty much every single part of our body. But it's a very important way to cleanse our bodies!

Viral genes are now incorporated into our DNA

Over the course of evolution, some retroviruses have integrated their DNA into the germ cells of our ancestors, which are the cells involved in reproduction. This means that the viral DNA became a heritable part of the genetic material transmitted from one generation to the next.
Image source/ Reddit
Not all our DNA is developed from our ancestors, we now have new DNA that has essentially developed from 'retro viruses' which have included viral DNA in our genes and they are now an important part of our genetic makeup, for example our reproduction.

There's more bacteria in us than 'human'

In essence, we are symbiotic organisms, coexisting with trillions of bacteria that make up our microbiome. Rather than being a threat, many of these bacteria are beneficial, contributing to our overall well-being in various ways. The symbiotic relationship between humans and their microbial companions is a testament to the complexity of the biological systems that define our existence.
Image source/ Reddit
It's probably a very unsettling thought for many people to discover that we actually have more bacteria inside our bodies than we do have 'human' elements, such as the atoms that make us up. In fact there's around 10 times more bacteria. But, a lot of this is beneficial!

A woman's eggs already exist when their mother is born

The notion that a woman's eggs, the very building blocks of future life, were already present within her mother's body when her mother herself was born is nothing short of mind-blowing. It's as if the potential for future generations is subtly woven into the fabric of existence from the very beginning.
Image source/ Reddit
The body is extremely complex and clever. To think that a woman's eggs already existed inside of her mother when her mother was born is mind-blowing. So the eggs that a woman is currently carrying were already in existence inside your mother when she was born!

Genes are only 3% of our DNA

Indeed, while DNA plays a pivotal role in shaping our biological characteristics and predispositions, it represents only a fraction of the intricate tapestry that determines who we are. The interplay between genetics and environment, known as nature versus nurture, underscores the dynamic and interactive nature of human development.
Image source/ Reddit
There is another 975 of DNA which are made up of other things that are equally important in controlling how we are and who we are. It is a very common myth to believe that the majority of us is made up and decided by DNA. There are many other factors involved in our development, some of which are not understood yet.

We are guided more by our unconscious brain than we think

Consider the scenario where we contemplate an action before executing it. In that seemingly contemplative moment, our unconscious brain is already in motion, laying the groundwork for the decision before it materializes in our conscious awareness. It's as if the subconscious mind has its own agenda, silently influencing and shaping our choices.
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We probably think that each decision we make is because of our conscious thoughts. But actually, even when we think about doing something and then do it, often our unconscious brain was already ticking over and acting before you made that decision. They are responsible for a lot of our brain activity.

Our vision isn't so accurate

Rather than functioning as passive cameras capturing an unaltered image of the external world, our eyes act as data collectors, gathering information about the light, colors, and shapes present in our environment. It is the brain's subsequent task to assemble this raw data into a coherent and meaningful visual experience.
Image source/ Reddit
We think that what our eyes see is solid proof. However our brain does something very clever in using information to construct our vision, rather than seeing EXACTLY what is there. Otherwise things would look a lot more unsteady due to light production etc...

Half of the population have eyelash mites

Picture this: as you go about your day, these minuscule arachnids, measuring only a fraction of a millimeter, may be quietly residing at the base of your eyelashes, feeding on the oils and dead skin cells. The fact that approximately half of the global population hosts these microscopic creatures might be surprising, yet the majority of individuals remain blissfully unaware of their presence.
Image source/ Reddit
If there's one thing we don't want to imagine, it's the fact that there's mites crawling around in our eyelashes. What a repulsive thought. But percentage wise it's very likely that we have them. Around half the population have them. You'd most likely never even know.

It's true, your nose and ears never stop growing!

While the idea of bodily transformations might evoke apprehension, it's crucial to emphasize the insignificance of these shifts. They occur on such a minor scale that they often escape notice, allowing us to carry on with our daily lives without being burdened by the thought of noticeable physical changes.
Image source/ Reddit
We've all heard it, and we are afraid to say that no, this is not a myth! It is indeed true. Which, really is not what a lot of people want to hear. But these changes are very small. In fact, most people would never be able to notice that their ears and noses have enlarged much at all.

We are made of 7 OCTILLION atoms

Atoms, the fundamental building blocks of matter, are incredibly minuscule entities, and yet, they are the elemental components that constitute everything in our tangible world.
Image source/ BBC
The human body is relatively large, so if you think about it we are made up of a lot of atoms, and atoms are miniscule. We are made up of 7 octillion to be precise, which for reference because this is a totally incomprehensible number is 7,000,000,000,000,000,000,000,000,000 atoms.

Our atoms are mainly empty space

It's truly fascinating to ponder the composition of our own bodies and realize that the seemingly solid matter is, on a microscopic level, predominantly composed of empty space.
Image source/ Reddit
What's even stranger to think, is that the atoms that make up our entire bodies are mainly filled with empty space. Fir example, the nucleus in the atom is the important part, but in size comparison this is like a country in comparison to the world. So actually, we are made up of a lot of emptiness.