The human body is a fascinating and complex machine. There are all sorts of strange facts about our bodies that you have likely never heard before. We’ve chosen 60 of the most interesting ones to share with you. Some of them will literally send you for a loop. For example, we’ll teach you about Exploding Head Syndrome. Yes, it’s a real thing!
Other facts are just as fascinating. From the help blowing on your thumb gives you, to learning about how far your heart can squirt blood across a room, this list has it just about everything. You might be surprised by just how much you don’t know about yourself.
1. The pink corner in your eyes is actually related to reptile and bird species.
It is believed an evolutionary remnant. It used to be an inner
eyelid similar to those that birds and reptiles have but it’s suggested that after millions of years of evolution, there is not much of it left.
2. Adults blink significantly more than babies do.
An average adult blinks about ten times each minute. However, a
baby will only blink once or twice in that same segment of time. Also, as most parents already know, babies rarely close their eyes during their waking hours.
3. Some people when falling asleep hear the sound of a bomb going off.
The name for this strange phenomenon is
exploding head syndrome. It sounds like a loud explosion or gunshot and happens right upon falling asleep or waking up.. It’s estimated that it affects up to 10% of the population.
4. The heart pumps about 200 million liters of blood in a lifetime.
The heart
contracts over 100,000 times every and every day. It is always doing its work and pumping away. And during exercise it can ever pump up to six times as fast as it normally does.
5. It’s possible for the human heartbeat to synchronize with music.
Depending on the beat and rhythm of the music that’s being listened to, the
heart beat can either speed up or slow down. Songs that have crescendos in them can cause blood vessels in the cardiovascular system to constrict.
6. Stomach acid is so strong it could burn a hole in skin.
Individual stomachs from person to person vary in levels of
acidity. However, the hydrochloric acid produced by the body is not only strong enough to break down food but in many cases, it can even bore a hole through a piece of wood.
7. The anus is the first thing to develop in a human embryo.
One would guess it would be the brain or literally anything else. However, it’s
true. The second thing to develop is the mouth, which when you think about it makes sense.
8. The jaw muscle is the strongest in the human body.
It does depend on how you measure strength. However, based on weight, the
jaw muscle comes in first place. This strength helps molars to chomp down with as much as 200 pounds of force.
9. It is possible that your body could have previously fought off cancer.
You wouldn’t necessarily even know, but
cells are constantly dividing. Because the body is pretty good at catching errors, if a cell notices that something is wrong, it is normally able to realize it’s not correct and fixes the problem before it gets out of control.
10. There is actually a syndrome where people become obsessed with fine dining.
It’s called
Gourmand Syndrome. It could happen due to an injury of the right anterior cerebral hemisphere of the brain. Afterward, the individual can have preference for eating and thinking about fine foods.
11. One quarter of the body’s bones is contained in the feet.
Each foot and ankle has a total of 26
bones. There are also 33 joints and over 100 muscles, tendons, and ligaments making the feet extremely complex areas of your skeletal system.
12. After only three months the fingerprints of a human embryo develops.
By the 17th week of pregnancy, the
fingerprints are pretty much already formed. After this point, they stay the same for the rest of a person’s life. Each and every fingerprint is completely unique.
13. The heart can squirt blood up to 30 feet.
It is a living pump with a lot of
pressure that can send blood all the way across a room. On top of this, the heart pumps around 2000 gallons of blood every day.
14. Human actually glow in the dark.
The human body is
bioluminescent, meaning in the dark, we give off light, but it is just too faint to be seen by the human eye. Species like fireflies and some jellyfish exhibit this property much more strongly.
15. Human hair is nearly indestructible.
One of the only real threats to
hair is fire. Other than that, it decays at a very slow rate. It’s even resistant to various types of acids and chemicals.
16. The small intestine is approximately 20 feet long.
In addition, the large intestine of humans is around five feet long. If you combine both
intestines together, it could make a rope that is long enough to jump out of a building three stories high.
17. If DNA were to be untwisted, it would be long enough to travel the solar system two times.
DNA is made up of coils. If they were to be unwound,
DNA would stretch all the way from Earth to Pluto and back again. In every single cell, there is about 2 meters worth of DNA.
18. The cornea in the eye does not have its own bloody supply.
It’s the only part of the body that doesn’t receive blood, and it’s simply because it doesn’t need it. The
cornea receives oxygen directly from the air it is exposed to instead.
19. You can help reduce stress and anxiety by putting your thumb near your mouth and blowing on it.
It sounds strange, but blowing on your
thumb is an easy way to help relieve stress. It works by cooling off the thumb and calming the pulse in it. This, in turn, causes the body to feel more relaxed in general.
20. The eye of a human can see at a resolution of 500 megapixels.
This
estimate includes the whole field of vision spanning 180 degrees. A very high definition camera would be needed to even come close to this.
21. It’s possible that kissing can help prevent cavities.
When people
kiss, their mouths produce more saliva. The extra fluid can help to wash away plaque and less plaque can mean fewer cavities next trip to the dentist.
22. The right kidney is lower than the left one.
]Organs aren’t always entirely symmetrical. The position of the
kidneys in the body is different with the left kidney being up higher than the right one.
23. The brain can generate enough electricity to power a light bulb.
The
brain is constantly sending electrical signals and impulses between the billions of neurons throughout. It that were to be combined all together, it could power a low-watt bulb.
24. If laid side by side, blood vessel length could circle the earth more than two times.
Between the arteries, veins, and capillaries, there are a lot of
blood vessels in the human body. They are winding all throughout every inch and if they were lined up, they would likely stretch between 60 to 100 thousand miles.
25. When people blush, their stomach lining does too.
Both the face and the stomach become red when
blushing. When the capillaries widen because of the blushing, this causes the extra red color.
26. Each person’s body contains about three to five pounds of bacteria.
People carry
bacteria around with them everywhere that they go. It can even be enough to fill up a soup can. All in all, the bacteria can make up around one to two percent of a person’s total body mass.
27. They are actually mites living on your eyelashes.
It’s a little strange to think about, but they inhibit other hair follicles too. The species of mites is known as
Demodex, and it’s possible they could be what is behind various skin disorders.
28. The human brain can survive for up to five to ten minutes with no oxygen.
Though a person will pass out usually after a minutes or two with no oxygen, the
brain will continue to function a while after that. Even after the heart stops, it will still take about six more minutes for brain death to occur.
29. About 16% of body weight is made up skin.
In the average adult eight, that means around 20 pounds or more of just
skin. If it were to be peeled off and laid out, it would cover an area of about 22 square feet.
30. Human and shark teeth have the same strength.
Although the
teeth of sharks are made from a harder mineral than our human teeth, they are still similar in their strength. It is mostly due to the enamel coating on them.
31. Astronauts can grow up to two inches taller while in space.
Without gravity weighing down the body, it can actually stretch out. Most
astronauts come back from space slightly taller than before they left. The astronaut who gained two inches was on a space station for about a year.
32. It is likely there is more bacteria in your mouth than people living on Earth.
Bacteria thrives in a warm and moist environment. There are at least 615 documented types of
bacteria and the levels in the mouth can number as high as in the billions.
33. If the brain were to be laid out flat, it would cover an entire pillowcase.
Though heads aren’t really that large, the
brain takes up a lot more space than we realize. All those wrinkles would have to be smoothed out to understand just how big it really is.
34. Up to 7,000 different facial expressions can be made by humans.
We have many more facial
muscles than primates. Also, with no hair on the face, it means that our expressions are easier to see.
35. There is enough fat in the human body to make up to ten bars of soap.
Obviously this can vary from person to person. Some people could be made into more or less
soap all depending upon the supply of fat reserves that they have.
36. During pregnancy the brains of women shrink.
Tt can take six months before the
brain returns to its normal size after childbirth. Though its a small change, it is observable. Once the baby is delivered, the brain slowly returns to it’s pre-pregnancy size.
37. Babies have more bones in their bodies than adults.
Infants are born with at least 300 or more
bones. But over time, many of these fuse together to eventually end up with a total of 212 bones.
38. Every hour humans shed about 600,000 particles of skin.
Each year a person loses about 1.5 pounds worth of
skin. In a span of a lifetime, it comes out to be about 100 pounds. Thankfully day by day it’s really not noticeable.
39. Every decade the human skeleton regenerates itself.
]The bones are regenerating day in and day out. At any given time, there is a large mix of new and older
bones in the body. Though the process never really stops, it does slow down as we age.
40. Your tongue print is just as unique as your fingerprint.
Though probably police stations won’t be asking for a print of your
tongue anytime soon. The tongue print needs to be recorded using a 3D imaging machine and they are quite expensive.
41. You are shorter each night you go to bed.
You are
tallest first thing in the morning when you rise. But over the course of the day, the spine gets compressed. The gelatin-like material in between your discs acts as a cushion then moves around while we sleep.
42. Even if 75% removed, the liver can regenerate to full size.
Even if three quarters of the
liver were to be taken away, it can still survive. It is the only organ in the body that has the capacity to regenerate and slowly grow back over time.
43. Our bodies are made of stardust dating back possibly billions of years.
People have about 97% of the same
atoms as the galaxy that we live in. Around 93% of the
mass of the body is actually stardust.
44. If the body is starving, the brain will start to eat itself.
This situation can even be caused by those who extreme diet. The scientific term for it is
autophagy and happens when cells in the body start to consume small portions of themselves to stay alive.
45. Most people dreamed in black and white in the 1940’s.
About three-quarters of Americans reported that they almost never saw
color in their dreams back then. The theory is because of black and white television and films. The percentage of people that report this phenomenon now is much smaller and interestingly nearly all shows and movies are in color.
46. Depending on whether we cry for sadness or happiness, our tears have different composition.
The emotion that causes the
tears to form matters. It has been discovered there There are three different types of tears and each one looks different when examined under a microscope.
47. There is a certain type of tumor that can grow on hair and teeth.
Though normally tumors grow on the skin or organs, there is a type of cyst called
teratoma that involve tissues like teeth, bone, and h air. Surgery can remove them.
48. By age 60, you will have lost around half of your taste buds.
Humans begin with about 10,000
taste buds when they are born. Taste buds actually only last around ten days before changing and over time the way things taste changes.
49. Even when removed from the body, the heart can continue beating.
About 5,000 times every year around the world heart
transplants are performed. Doctors keep the heart beating while they transport it to the patient receive it.
50. The highest fever on record is 115 degrees Fahrenheit.
The person
survived. Normal human body temperature is 98.6° F and anything above 100.4 is cause for concern For most people, multiple organ failure starts to occur around 107 degrees.
51. Wherever there are two of an organ, only one is required for survival.
For example, even if one of the lungs is lost, a normal
life can still be lived with just one. A person just won’t be able to exercise as vigorously as they could before. The same idea applies to kidneys.
52. It is not possible to breath and swallow at the same time.
A lot of other animals can, but not
humans. Because of the placement of our voice box it has to be one or the other at a single time.
53. There is 10 times as much bacterial in the human body are there are cells.
Bacteria is much more plentiful in the body than actual cells. The giant
microbial communities have a serious impact on our health.
54. Our mouths produce one to two liters of spit each day.
That’s enough to fill two to four water bottles. The
salivary glands can be triggered just by thinking about food. And, of course, when you are eating they are working even harder.
55. When submerged in water, the body triggers a “diving reflex.”
This reflex causes certain systems in the body to shut down to conserve energy. This causes actual physiological changes. It is clear from the
research that humans actually have a long aquatic history.
56. Even when were are awake, our eyes are closed 10% of the time.
This is mostly due to time spent
blinking. A blink only lasts a split second, but we blink a lot. The average person blinks around 15 to 20 times each minute.
57. The enzymes that digest your food also will digest your body after you die.
After death, the
enzymes are still working. The microbial organisms can feed on the fluids produced during autolysis — the process that occurs once a person passes away.
58. Each decade after 30, a person loses about half an inch in height.
As people grow older, they also get
shorter. The reason is the discs between the vertebrae start to flatten. It happens so slowly that most won’t even notice the change in height.
59. Having a broken heart actually causes a real heart condition.
It is called
broken heart syndrome and it’s real thing. The emotional stress can cause chest pain and shortness of breath similar to a heart attack. Thankfully it normally resolves within a few days or weeks.
60. The kidneys filter all the blood in the body 25 times per day.
This comes out to around 180 liters of
blood processed each day. The average body contains seven or eight liters in total. This kidney filtration is crucial to keeping the blood in a healthy state.