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

By molly atherton 8 months ago
Forget what you think you know about anatomy; we're about to dive into the hidden enigmas that make our bodies a playground of curiosity. From microscopic realms to the uncharted territories of our senses, prepare to be enthralled as we unravel the mind-bending phenomena that defy explanation. Join us on a thrilling journey through the lesser-explored wonders of the human body. Brace yourself for an eye-opening adventure into the mysteries you never knew existed.

1. You'll have a new skeleton in 10 years

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?Original content sourced from

Image Source: Reddit

The human skeletal system is a dynamic and living tissue, contrary to the common misconception of bones being static and unchanging. This dynamic nature is owed to a continuous process called bone remodeling, which involves the removal of old or damaged bone tissue and the formation of new bone.

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

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.

Image Source: Reddit

When you pinch something between your thumb and index finger, it's easy to notice the role of the thumb in opposition to the other fingers. However, the pinkie plays a vital supporting role in this action. As you pinch, the muscles in the pinkie stabilize the hand.

3. You can’t tickle yourself

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.

Image Source: Smithsonian Magazine

The brain constantly receives feedback from the body through a complex network of sensory receptors. These receptors inform the brain about the body's position, movement, and interactions. In the case of self-tickling, the brain uses an internal feedback loop to predict your own actions.

4. Humans are just as hairy as chimpanzees

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.

Image Source: Reddit

Over the course of human evolution, as our ancestors adapted to different environments, there was a gradual reduction in body hair. This reduction is believed to be linked to factors such as thermoregulation, as less body hair allowed early humans to cool off more efficiently.

5. Babies aren’t born with kneecaps

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.

Image Source: Reddit

The timing of kneecap formation aligns with the broader pattern of skeletal development in humans. Many bones in the body undergo a similar transformation from cartilage to bone during childhood and adolescence, contributing to the overall growth and maturation of the skeletal system.

6. Everyone has a unique tongue print

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.

Image Source: Reddit

The uniqueness of tongue prints is attributed to a combination of factors, including the arrangement of papillae (tiny bumps on the tongue), the presence of taste buds, and the overall topography of the tongue's surface. The patterns just aren't as visibly pronounced as fingerprints.

7. Human bones are stronger than steel

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!

Image Source: Reddit

The key to this strength lies in the intricate structure of bones. Bones are composed of collagen, a flexible protein that provides tensile strength, and hydroxyapatite, a mineral that contributes to hardness and compression strength. This combination creates a material that is both flexible and rigid.

8. Stomach acid can dissolve metal

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!

Image Source: Freepik

The digestive fluid in the stomach is composed of hydrochloric acid, enzymes, and other substances that work to create a very acidic environment. This acidity serves multiple functions, including the activation of digestive enzymes and the breakdown of food into smaller, digestible components

9. Humans are the only species that cry

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.

Image Source: Reddit

The ability to shed tears in response to emotions is believed to have evolved as a form of non-verbal communication. Emotional tears can convey a range of social signals and serve as a means of expressing vulnerability, empathy, or a need for support.

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

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.

Image Source: ResearchGate

The hyoid bone serves as a base and anchoring point for the tongue muscles, allowing it a remarkable degree of flexibility and range of motion. The other end of the tongue is free and not directly attached to a bone. This unique arrangement enables the intricate movement required for speech.

11. Having dirty hair helps the environment

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!

Image Source: Reddit

Hair, particularly the cuticle layer that forms the outermost protective part of the hair shaft, has properties that can interact with and absorb various environmental elements. The cuticle layer of the hair consists of overlapping scales that can create a porous surface.

12. The smallest bone in the human body is in your ear

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.

Image Source: Reddit

Despite its diminutive stature—measuring only a few millimeters in length—the stapes plays a crucial role in the amplification and transmission of sound waves. The sensitivity of the auditory system allow humans to perceive a wide range of sounds and frequencies.

13. The human intestine is 4x as long as you are

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.

Image Source: Freepik

The coiling of the small intestine serve multiple purposes. First and foremost, this structural arrangement provides a substantial surface area for the absorption of nutrients which is enabled by the inner lining of the small intestine which is covered with tiny projections called villi..

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

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.

Image Source: Daily Yogi

When you lie down to sleep, especially in a horizontal position, the spine is relieved of the day's compression, allowing the cartilage to rehydrate and the intervertebral discs to expand. This rehydration and expansion contribute to a temporary increase in height.

15. Sneezes can travel as far as 20 feet

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!

Image Source: MyLondon

So, the next time you consider the reach of a nearby sneeze, remember that the expelled droplets can travel much farther than you might intuitively think, highlighting the importance of taking precautions to minimize the risk of respiratory transmission.

16. A quarter of your bones are in your feet

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.

Image Source: Reddit

Additionally, the foot is richly innervated and vascularized, contributing to its sensitivity and responsiveness to various stimuli. This intricate structure reflects the evolutionary adaptations that have allowed humans to move efficiently and adapt to different terrains throughout history.

17. Your hair knows your sleeping pattern

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.

Image Source: Reddit

These genes are expressed in different tissues throughout the body, including the hair follicles. Research has suggested that the expression of certain clock genes in hair follicles may reflect the circadian rhythm and, by extension, provide insights into an individual's sleep-wake cycle.

18. There are no muscles in your fingers

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.

Image Source: Reddit

The palm of the hand does contain intrinsic muscles, which are responsible for controlling certain movements of the fingers and thumb. These muscles work in conjunction with the tendons and extrinsic muscles in the forearm to produce a wide range of hand movements.

19. You lose a third of your bones as you get older

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.

Image Source: Essex TV

Ossification is the gradual conversion of cartilage or soft connective tissue into bone. This process begins during fetal development and continues into early adulthood. The fusion of bones is a natural and necessary part of the skeletal development.

20. The largest muscle in your body is the gluteus maximus

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.

Image Source: Reddit

As you mentioned, the gluteus maximus is the main extensor muscle of the hip. It is responsible for actions such as hip extension, which is the movement of the thigh backward, as well as external rotation and abduction of the hip. These movements are essential for our movement.

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

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.

Image Source: Reddit

While cilia play a crucial role in maintaining the health of the respiratory system, the detection of taste and the sensation of bitterness are typically associated with taste buds on the tongue rather than the cilia that live in the respiratory passages.

22. Your nails will grow more quickly today than they did yesterday

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.

Image Source: Reddit

The growth rate of nails is relatively consistent among individuals and is generally estimated to be around 1/8 inch or 3 mm per month for fingernails. Factors such as age, hormonal changes, and certain medical conditions can also affect the growth rate of nails.

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

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.

Image Source: Freepik

The regenerative capacity of the liver is not unlimited, and certain conditions, such as chronic liver diseases or repeated injury, can impair the regenerative process. Nonetheless, the liver's ability to regenerate is a crucial aspect of its function and contributes to its resilience.

24. Having a bad posture can affect your memory

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.

Image Source: Reddit

For example, a study published in the journal "Psychonomic Bulletin & Review" in 2015 found that participants who adopted an upright posture were more likely to recall positive memories, while those in a slouched posture were more likely to recall negative memories.

25. The bigger your eyes, the worse your eyesight could be

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.

Image Source: Reddit

While the size of the eyes is not the sole determinant of myopia, there is an association between larger eyeball size and an increased risk of developing nearsightedness. Individuals with larger eyes often have longer axial lengths, meaning the distance from the front to the back of the eye is greater.

26. The human body glows but you can’t see it

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.

Image Source: Pinterest

Biophotons are extremely weak emissions of light that result from biochemical reactions within living cells. These light emissions are part of the broader field of bioluminescence, which refers to the production and emission of light by living organisms.

27. Blinking is the equivalent of having a mini nap

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.

Image Source: Exclusively Eyecare

Studies have suggested that purposeful blinking, such as during periods of sustained attention or when processing complex information, helps the brain to briefly disengage from external stimuli. This momentary break may contribute to cognitive efficiency.

28. Your tastebuds get less sensitive as you get older

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.

Image Source: Reddit

Taste buds are clusters of cells on the tongue that contain taste receptors. These receptors detect different flavors—sweet, salty, sour, bitter, and umami. With age, the regeneration of taste cells can slow down, leading to a reduction in the overall number of functional taste buds.

29. Our stomach has its own brain

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!

Image Source: Pinterest

The gut, often referred to as the "second brain" or the enteric nervous system (ENS), is indeed lined with a network of neurons that are in constant communication with the central nervous system (CNS), meaning you feel a range of emotions and feelings!

30. 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

Humans possess a diverse array of sensory systems that contribute to their ability to navigate and interact with the environment. Thermoception, or the ability to sense temperature, is facilitated by thermoreceptors located in the skin and internal organs.

31. The whole of our skin is replaced each month

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!Image source/ RedditThe outer layer of the skin, known as the epidermis, undergoes constant renewal as old skin cells are shed and replaced by new ones. This process typically takes about a month, although the exact duration can vary among individuals and in different regions of the body.

32. Each minute we shed around 30,000 dead skin cells

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?Image source/ RedditThe outer layer of our skin, the epidermis, continuously sheds dead skin cells as part of the natural process of cellular turnover. These tiny, lightweight skin cells become airborne and contribute to the dust particles that accumulate in our living spaces.

33. Your appendix hasn't lost its function after all!

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.Image source/ RedditIn this proposed function, the appendix may act as a reservoir for beneficial bacteria, helping to maintain a healthy balance of microorganisms in the gut. This idea aligns with the concept of the microbiome, which refers to the community of microorganisms, including bacteria.

34. Females contain way more DNA than males

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.Image source/ geneticliteracyThe X chromosome is indeed larger and carries more genetic information than the Y chromosome. The X chromosome contains a diverse array of genes responsible for various functions in the body, including those related to development, immune response, and sensory perception.

35. You blink around 20 times a minute

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...Image source/ RedditBlinking serves several essential functions, including moisturizing the eyes, spreading tear film, and protecting the eyes from foreign particles. While it might seem like a lot of time spent with our eyes closed, each blink allows for continuous perception of the surrounding environment.

36. The tongue is covered in around 8,000 taste buds

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.Image source/ RedditTaste buds are small sensory organs located on the tongue and other parts of the mouth. They contain specialized cells, known as gustatory cells, which are responsible for detecting different tastes—sweet, salty, sour, bitter, and umami. Each taste bud consists of clusters of these cells.

37. Goosebumps are a feature of our ancestral past

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 amotion. When animals get scared they fluff up their hair to look more threatening. We still do this, without the excessive fur.Image source/ CBCIn humans, the emotional trigger for goosebumps can extend beyond fear to other strong emotions, such as excitement, awe, or even listening to moving music. This response is linked to the autonomic nervous system, specifically the sympathetic nervous system.

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

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.Image source/ RedditNasal mucus helps moisturize the delicate tissues lining the nasal passages, preventing them from drying out. Additionally, the mucus acts as a trap for airborne particles, such as dust, bacteria, and viruses, preventing them from reaching the lungs.

39. The only muscle that never gets tired is your heart

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!Image source/ RedditUnlike our skeletal muscles, which can experience fatigue after sustained activity and require periods of rest and recovery, the heart muscle, or myocardium, has a special set of characteristics that enable it to function continuously without fatigue.

40. The body has 2.5 millions sweat pores

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!Image source/ RedditThese glands are most concentrated on the palms of the hands, the soles of the feet, and the forehead. Sweat is primarily composed of water, electrolytes, and trace amounts of other substances. The primary purpose of sweating is to regulate body temperature.

41. Viral genes are now incorporated into our DNA

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.Image source/ RedditOur DNA, which contains our genetic instructions, doesn't just come from our ancestors. We also have bits of DNA that come from viruses—or, retroviruses. These viruses inserted their genetic material into our ancestors' DNA. Over time, these viral bits have become a normal and important part of our genetic makeup.

42. There's more bacteria in us than 'human'

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!Image source/ RedditThe majority of these microorganisms reside in our digestive system, particularly in the colon, where they form what is known as the gut microbiota. While it might sound surprising, many of these bacteria are beneficial and play crucial roles in our health.

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

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!Image source/ RedditThis process highlights the incredible complexity and continuity of life. The genetic material that could potentially contribute to the formation of future generations is established very early in the development of a female fetus. It's a remarkable aspect of human biology.

44. Genes are only 3% of our DNA

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.Image source/ RedditEpigenetic (environmental) factors involve changes to gene expression that do not alter the underlying DNA sequence. These changes can be influenced by environmental factors, lifestyle, and experiences, and they can impact how genes are "read" and utilized.

45. We are guided more by our unconscious brain than we think

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.Image source/ RedditResearch has shown that the brain is continually processing information at an unconscious level. This includes assessing risks, and preparing responses before we are aware of it. Sometimes, decisions that seem to arise from intuition or gut feelings are associated with rapid, unconscious processing.

46. Our vision isn't so accurate

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..Image source/ RedditOur brain "fills in" missing information or gaps in our visual field. For example, we have a blind spot in each eye where the optic nerve connects to the retina, but we rarely notice it because the brain fills in the missing information based on surrounding visual input.

47. Half of the population have eyelash mites

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.Image source/ RedditDemodex mites are super common and often go unnoticed because they are typically harmless and don't cause noticeable symptoms. These mites spend their entire lives on or near hair follicles. They feed on oils and dead skin cells and are more active during the night.

48. It's true, you nose and ears never stop growing!

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.Image source/ RedditThe ears and nose are primarily composed of cartilage rather than bone. Over time, the cartilage in these areas may undergo changes due to a combination of factors, including the effects of gravity, changes in skin elasticity, and the gradual breakdown of collagen.

49. We are made of 7 OCTILLION atoms

Image source/ BBCAtoms are the fundamental matter, and they combine to form molecules, which, in turn, make up the cells, tissues, and organs of the human body. The human body is composed of a variety of elements, with oxygen, carbon, hydrogen, nitrogen, calcium, and phosphorus being some of the most abundant.

50. Our atoms are mainly empty space

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.Image source/ RedditElectrons, which are much smaller and lighter than protons and neutrons, orbit the nucleus in a cloud-like region. However, the exact positions of electrons are not fixed; instead, they exist within a probability cloud, indicating the likelihood of finding an electron in a particular location.