De nos jours, grâce aux progrès de la dentisterie, la plupart des gens conservent leurs dents beaucoup plus longtemps. Nous pouvons facilement remplacer les dents perdues si nécessaire, rendant les dents de sagesse moins nécessaires. Fait intéressant, moins d'adultes doivent faire face aux douleurs de dentition. Au cours des 10 000 dernières années, nos mâchoires ont évolué rapidement, surtout à mesure que nos régimes alimentaires passaient de la chasse à l'agriculture. C'est juste l'un des nombreux faits qui prouvent à quel point votre corps est impressionnant et unique. Préparez-vous à en apprendre davantage et à voir votre propre corps sous un angle différent. Animation créée par Sympa.
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Musique par Epidemic Sound https://www.epidemicsound.com
Pour ne rien perdre de Sympa, abonnez-vous!: https://goo.gl/6E4Xna
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Nos réseaux sociaux :
Facebook: https://www.facebook.com/sympasympacom/
Instagram: https://www.instagram.com/sympa.officiel/
Stock de fichiers (photos, vidéos et autres):
https://www.depositphotos.com
https://www.shutterstock.com
https://www.eastnews.ru
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Si tu en veux encore plus, fais un tour ici:
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FunTranscript
00:00Let's get back to the face now.
00:02Open your mouth and say ah ah.
00:06If you are lucky enough not to have wisdom teeth,
00:09then you can be proud to know that you are a pure product of evolution.
00:14As you may know, teeth are the only part of the human body that does not repair itself.
00:20If you lost all your teeth at this dark time when there were no dentists,
00:24your only option was to consume only liquid food.
00:30Scientists think that nature gave us wisdom teeth
00:33to replace the older and worn teeth we have since childhood.
00:37That's why they grow so late in our lives.
00:40But today, with all the progress made by dental surgery,
00:44we tend to keep almost all our teeth intact until an advanced age.
00:49And even if we lose some, we can always replace them.
00:53This makes wisdom teeth a little outdated vestige,
00:56which it seems to understand by itself,
00:58since less and less people need to undergo the ordeal
01:01that their adult extraction represents.
01:04Speaking of teeth, our entire jaw has evolved over the last 10,000 years.
01:10And it is expected that it will change even more in the future.
01:13In fact, of all the parts of our body, it is the one that has transformed the fastest.
01:18When the first humans survived thanks to hunting and gathering,
01:22they needed massive and powerful jaws, as well as larger teeth
01:26to be able to chew raw meat and grind plants.
01:29When they started to cook, then to cultivate,
01:32their food became less hard and their jaws adapted accordingly.
01:38Over time, they have shrunk more and more,
01:41and it is likely that they will continue to do so.
01:44With a lot of transformed food that doesn't require a lot of chewing,
01:48future humans will probably have more delicate facial features,
01:52thin jaws and smooth jaws.
01:56Some parts of the body don't disappear,
01:58but on the contrary, they return to life.
02:01A hundred years ago, the fabella, a tiny bone located at the back of the knee,
02:05was only present in about 11% of people,
02:08and scientists thought it would disappear entirely and quickly.
02:12But against all odds,
02:14this brave little bone managed to end up in the knees of 39% of humans today.
02:21We still don't know exactly why the fabella came back,
02:24but the most plausible hypothesis is that we have become bigger and heavier than our ancestors.
02:30As our food has become of better quality and more nutritious,
02:35our size and our life expectancy have increased.
02:37Today, we are probably at the peak of our evolutionary size.
02:42And the fabella may have appeared in our body
02:44to provide a smooth surface to the tendon behind the knee
02:47so that it can slide better,
02:49thus reducing friction and the risk of damage due to wear.
02:55Speaking of size, let's go back to our mirror.
02:59Stretch out your arms a little.
03:01Look at those pretty biceps.
03:03Unfortunately, they are probably not as developed as those of your ancestors.
03:07Everything that comes from evolution is not always what we consider to be the best for us.
03:11It is above all a set of characteristics,
03:13in principle the best adapted to our lifestyles.
03:16And this is also the case with our muscles.
03:18They have become smaller and stronger over time,
03:20especially in the upper part of our body.
03:23In the past, humans needed a great muscular power
03:26that they mobilized to carry out all kinds of essential manual work,
03:30such as hunting and transport of prey,
03:32as well as the manufacture of tools and the construction of shelters.
03:35Then, it did not become easier.
03:37On the contrary,
03:38ploughing the fields and building complex structures
03:41required a lot of physical strength and endurance.
03:43But with the rise of technological progress,
03:45physical abilities have left more and more energy
03:48dedicated to brain functions,
03:50allowing us to invent machines
03:52that sometimes work more efficiently in our place.
03:56We are oriented towards a sedentary lifestyle,
03:59spending more and more time sitting in front of screens.
04:02In general, our musculature has not ceased to decrease,
04:05because it is less and less necessary to us.
04:09It is very likely that as progress progresses,
04:12we will see our strength diminish
04:14and we will have more difficulty gaining muscle mass.
04:18Our brain is particularly interesting,
04:21because it has evolved in a rather strange way.
04:24At first, our distant ancestors had a rather small brain,
04:28but the close relatives of the Homo sapiens,
04:30the Neanderthals,
04:31had a brain larger than that of the average modern man.
04:35As evolution progressed,
04:37the human brain grew larger.
04:39But over the most recent centuries,
04:41it began to shrink,
04:43and no one knows exactly why.
04:45Some experts claim that this could be related
04:48to the change in our lifestyles and our socialization.
04:51The first humans, especially the hunter-gatherers,
04:54had to remember each plant and animal they saw,
04:57their property and how to use this or that thing.
05:00They had more general knowledge,
05:02learning everything their parents knew
05:04and discovering even more by themselves.
05:07Modern humans have a more specialized knowledge in a certain field,
05:11deepening a specific subject while relying on their parents for the rest.
05:15While our ancestors worked mostly in groups
05:18in which everyone knew more or less everything
05:20and could replace each other,
05:22we tend to form teams
05:24where each member has a specific task and is irreplaceable.
05:28After all, the size of the brain does not seem to have such a capital importance.
05:32Orcs and elephants, for example,
05:34have a brain much larger than ours,
05:36which does not necessarily make them smarter.
05:39I don't want to scare you or anything,
05:41but know that every second, your body creates 25 million new cells.
05:45I'm going to do the math for you.
05:47That means that in about 15 seconds,
05:49you will have produced more cells than there are people in the United States.
05:53Think about it the next time you feel like you haven't been productive enough.
05:57It may only represent 2% of our body mass,
06:00but our brain absorbs 20% of our blood and oxygen intake.
06:04Our brain can also produce enough energy
06:07to power an electric bulb, at least when we are awake.
06:10Have you ever wondered what the largest human organ is?
06:13It's your skin.
06:14And it's on the palm of your hand and the plant of your feet that it is the thickest.
06:18I know, I know, I hate dust too,
06:21but you are partly responsible for this film of filth on your TV screen.
06:25Yes, human beings lose about 600,000 skin particles in an hour.
06:31And the biggest part of the dust you have at home is actually composed.
06:35You have a nice layer of it too.
06:38Nowadays, we consider it more of a beauty mark.
06:41But the reason why people are born with what is called a Cupid's bow is actually quite fascinating.
06:46As our traits begin to develop even before our birth,
06:49it seems that the Cupid's bow is actually the place where our face, well, closes,
06:55where the right and left sides meet.
06:58For humans, this may not be so obvious,
07:01but if you look at the muzzle of your dog,
07:03you will see that there is a vertical line, all straight, just below the nostrils.
07:07Yes, dogs also have their Cupid's bow.
07:10Did you know that you were born with more water than you have today?
07:13At birth, we have about 300 bones.
07:16But as we age, some of them merge.
07:19This is why at adulthood, we end up with about 200 bones.
07:24Although your teeth are mainly part of your skeleton,
07:27they are not really bones.
07:29However, they look like them and share some characteristics with them,
07:33such as being the hardest elements of your body.
07:36But why were you born with them?
07:38Mainly because teeth and bones contain both calcium.
07:41To be a little more precise,
07:43about 99% of the calcium in our body is in our bones and teeth.
07:47The rest is in our blood.
07:49So what differentiates them, you ask?
07:52Well, it's a question of regeneration and, of course, of care.
07:56Your bones can repair and heal themselves,
07:59but your teeth are not able to do it.
08:01That's why we have dentists.
08:03We don't just have unique fingerprints.
08:05Our tongues are too.
08:07Research has shown that the few 10,000 taste buds that cover it
08:11are arranged according to a unique pattern, specific to each individual.
08:16About 80% of what you think is the taste of something is actually its smell.
08:20The combination of taste and smell is what we call taste.
08:26It's probably because our smell is about 10,000 times more powerful than our sense of taste.
08:33The next time you listen to your favorite song,
08:35try to pay attention to the beat of your heart.
08:38Do you hear that?
08:39Yes, it's true.
08:40When you listen to music,
08:42the beats of your heart synchronize with the rhythm of the song.
08:45And speaking of your heart,
08:47sometimes you ask yourself the question,
08:49when it is in good health, it goes on average 75 times per minute.
08:53This means that over a year,
08:55a human heart can pump enough blood to fill an Olympic swimming pool.
08:59What is even more fascinating,
09:01is that if you connect all your blood vessels end to end,
09:04you will be able to go around the Earth four times.
09:07But that would really hurt, so don't try it.
09:10We are the only species on Earth to have a chin.
09:13This subject is still the subject of debate in the scientific community,
09:17but one of the reasons seems to be that the chin would make our jaws stronger.
09:21As humans have evolved,
09:23their teeth and jaw muscles have become smaller and smaller.
09:27So they needed something to help them increase the power of their jaws.
09:31The transparent part of your eye is called the cornea,
09:34and it favors the passage of light.
09:36It is also the only part of your heart that is not connected to your blood system.
09:40Why?
09:41Because it is designed to get the oxygen it needs directly from the surrounding air.
09:46If you remove all the fat present in a healthy human body,
09:50it would be enough to make seven parts of soap.
09:53We also produce enough saliva during our life to fill two swimming pools.
09:57So, do we prick a head?
10:00Do you know the amount of food you ingest during a lifetime?
10:04I will spare you the calculations.
10:06An average person eats nearly 33 tons of food from birth to death.
10:11What is this compared to, to get an idea?
10:13Well, that's about six elephants.
10:15In peanuts, that's a lot more.
10:17We all carry on average about 1.8 kg of bacteria at any time in our body.
10:23But don't run so fast to the doctor.
10:26Most of these bacteria are actually good for you.
10:29They have specific functions in the human body.
10:31For example, for digestion and the immune system.
10:35If you want to get a precise idea of your size, make sure you measure yourself in the morning.
10:40Because you are taller by about a centimeter when you wake up.
10:45Believe me, it's not magic.
10:47It's simply because throughout the day,
10:49the cartilage between the bones and the spine crumbles and compresses,
10:53which makes you smaller when you go to bed.
10:57Your skeleton is completely renewed in ten years.
11:00Yes, without surgery.
11:03An adult uses about 200 muscles to take a single step.
11:07So, don't tell me I don't do enough exercise.
11:11Every minute, your body loses more than 3,000 skin cells.
11:15This represents nearly 200,000 skin cells per hour and more than 3 kg per year.
11:21Hey, that's the plan to lose weight by losing skin cells.
11:24Oh, sign up.
11:26But don't worry, you still have about 300 million skin cells at some point.
11:31In addition, your skin is completely renewed every 28 to 30 days.
11:36The liver is the only human organ that can regenerate completely.
11:4025% of the liver's initial weight is enough for it to return to its normal size.
11:46Some people can hear their eyeballs moving in their orbits.
11:50Wow, that must not be funny.
11:53Unlike other parts of your body, your ears and nose never stop growing.
11:57Wow, that must not be funny.
12:00Your skin freezes if you stay in the water for too long.
12:03But not because it absorbs water.
12:06When your body is wet, your fingers and toes allow you to have a better grip.
12:11You know, like when the tires on your car grip better on the road when they are new.
12:16Your eyes are an amazing tool.
12:19They can distinguish 10 million different colors.
12:23Your brain uses more than 20% of your body's energy even when you're resting.
12:28When you sleep, it still consumes almost as much energy as when you're awake.
12:32In addition, it burns about 330 calories a day.
12:37An adult person has about 25% of all his water in his feet.
12:41Most of them are tiny but crucial.
12:44If these waters are not aligned, the rest of the body is not either.
12:49You breathe about 20,000 times a day.
12:52Try not to stop.
12:53In fact, I set a personal breathing record for several consecutive days today,
12:58and I plan to beat it tomorrow.
13:01Waters are a real paradox.
13:03They are almost five times more resistant than a steel bar of the same width.
13:07But they can break at the impact and are rather fragile.
13:11If a person is affected by anosmia, also called olfactory cystitis,
13:15they cannot distinguish and detect odors.
13:18But they can still smell bad.
13:20Sorry.
13:22You start to get thirsty when the loss of water represents 1% of your body weight.
13:26More than 5% and you risk fainting.
13:29A loss of water greater than 10% of the body weight
13:32and dehydration can kill a person.
13:35Not a nice ending.
13:38The strongest muscle of your body, depending on its weight, is that of your jaw.
13:42Yes, mine is far too developed.
13:45At any time, 50,000 cells of your body are replaced by new ones.
13:50It looks like a company I worked for.
13:53At the end of his life, a normal person can remember up to 150 trillion pieces of information.
13:58Except for the place where they left their car keys.
14:02Even if digital fingerprints are seriously damaged,
14:05they grow back with their original pattern.
14:07You don't believe me? Give him a whip.
14:11The memory capacity of your brain is equivalent to about 4 Teraoctets on a hard drive,
14:16which represents more than 8 million photos.
14:19Man is the only living being able to naturally sleep on his back.
14:23Even monkeys generally sleep in a sitting position, leaning on something.
14:27Don't wake them up.
14:29The longest bone is the femur and not the laughing bone.
14:33And the smallest is in the ear. It is shorter than a grain of rice.
14:37Do you feel tickles when you tickle yourself?
14:40Normally, you shouldn't.
14:42Except if someone else tickles you.
14:44Normally, you shouldn't.
14:46Except if someone else tickles you.
14:48This happens because the area of the brain's cerebellum, which monitors the movements,
14:52predicts the sensations caused by your own movements.
14:55Then, it sends a signal to other parts of the nervous system to cancel these sensations.
15:01But few people can feel ticklish of their own head.
15:05If you are not one of these people,
15:07touching a new texture that the brain does not yet recognize,
15:11or using a scalp massager,
15:13can help excite your nerves and relax you.
15:16You can also do a tickling test.
15:19If you want to check the work of your vestibular system,
15:22try this simple trick.
15:24Stand on one foot and close your eyes.
15:27Most people lose their balance, at least during the first attempt.
15:30Your vestibular system includes many organs and systems distributed throughout your body.
15:35Together, they allow your body to remain balanced in different positions.
15:39This system includes the inner ear and the vision.
15:42This is why it is much easier to keep your balance in silence when your eyes are open.
15:48Can you move your ears voluntarily?
15:50Are you popular in parties because you know how to do it?
15:53Congratulations!
15:54About 22% of the earth's inhabitants are able to move their ears.
15:59As for moving both ears at the same time, only 18% can do it.
16:04Moving your ears was a common practice among our distant ancestors.
16:08Scientists think they could do a whole series of movements with their ears.
16:13The group of muscles responsible for this is called the auriculars,
16:16and we generally don't need them nowadays.
16:19But some people claim that everyone can learn to move their ears.
16:23This only takes time and practice.
16:25Unfortunately, we cannot yet acquire this famous habit of
16:29stretching the ear towards a sound source like dogs and cats do.
16:33We cannot lend our ears to someone either.
16:36They are difficult to remove and attach.