Facts About the Human Body
by Christina Laud
Posted August 01, 2010; updated October 18, 2021.
The human body is an incredibly complex and intricate system, one that
still baffles doctors and researchers on a regular basis despite thousands
of years of medical knowledge. As a result, it shouldn’t be any surprise
that even body parts and functions we deal with every day have bizarre or
unexpected facts and explanations behind them. From sneezes to fingernail
growth, here are 100 weird, wacky, and interesting facts about the human
body.
The Brain
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The human brain is the most complex and least understood part of the
human anatomy. There may be a lot we don’t know, but here are a few
interesting facts that we’ve got covered.
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- Nerve impulses to and from the brain travel as fast as 170
miles per hour. Ever wonder how you can react so fast to things
around you or why that stubbed toe hurts right away? It’s due to the
super-speedy movement of nerve impulses from your brain to the rest of
your body and vice versa, bringing reactions at the speed of a high
powered luxury sports car.
- The brain operates on the same amount of power as 10-watt
light bulb. The cartoon image of a light bulb over your head
when a great thought occurs isn’t too far off the mark. Your brain
generates as much energy as a small light bulb even when you’re
sleeping.
- The human brain cell can hold 5 times as much information as
the Encyclopedia Britannica. Or any other encyclopedia for that
matter. Scientists have yet to settle on a definitive amount, but the storage capacity of the brain in
electronic terms is thought to be between 3 or even 1,000 terabytes. The
National Archives of Britain, containing over 900 years of history, only
takes up 70 terabytes, making your brain’s memory power pretty darn
impressive.
- Your brain uses 20% of the oxygen that enters your
bloodstream. The brain only makes up about 2% of our body mass,
yet consumes more oxygen than any other organ in the body, making it
extremely susceptible to damage related to oxygen deprivation. So
breathe deep to keep your brain happy and swimming in oxygenated cells.
- The brain is much more active at night than during the day.
Logically, you would think that all the moving around,
complicated calculations and tasks and general interaction we do on a
daily basis during our working hours would take a lot more
brain power
than, say, lying in bed. Turns out, the opposite is true. When you turn
off your brain turns on. Scientists don’t yet know why this is but you
can thank the hard work of your brain while you sleep for all those
pleasant dreams.
- Scientists say the higher your I.Q. the more you dream.
While this may be true, don’t take it as a sign you’re mentally
lacking if you can’t recall your dreams. Most of us don’t remember many
of our dreams and the average length of most dreams is only 2-3
seconds–barely long enough to register.
- Neurons continue to grow throughout human life. For
years scientists and doctors thought that brain and neural tissue
couldn’t grow or regenerate. While it doesn’t act in the same manner as
tissues in many other parts of the body, neurons can and do grow
throughout your life, adding a whole new dimension to the study of the
brain and the illnesses that affect it.
- Information travels at different speeds within different
types of neurons. Not all neurons are the same. There are a few
different types within the body and transmission along these different
kinds can be as slow as 0.5 meters/sec or as fast as 120 meters/sec.
- The brain itself cannot feel pain. While the brain
might be the pain center when you cut your finger or burn yourself, the
brain itself does not have pain receptors and cannot feel pain. That
doesn’t mean your head can’t hurt. The brain is surrounded by loads of
tissues, nerves and blood vessels that are plenty receptive to pain and
can give you a pounding headache.
- 80% of the brain is water. Your brain isn’t the
firm, gray mass you’ve seen on TV. Living brain tissue is a squishy,
pink and jelly-like organ thanks to the loads of blood and high water
content of the tissue. So the next time you’re feeling dehydrated get a
drink to keep your brain hydrated.
Hair and Nails
While they’re not a living part of your body, most people spend a good
amount of time caring for their hair and nails. The next time you’re heading
in for a haircut or manicure, think of these facts.
- Facial hair grows faster than any other hair on the body.
If you’ve ever had a covering of stubble on your face as you’re
clocking out at 5 o’clock you’re probably pretty familiar with this. In
fact, if the average man never shaved his
beard it would grow to over 30 feet during his lifetime, longer than a killer whale.
- Every day the average person loses 60-100 strands of hair.
Unless you’re already bald, chances are good that you’re
shedding pretty heavily on a daily basis. Your hair loss will vary in
accordance with the season, pregnancy, illness, diet and age.
- Women’s hair is about half the diameter of men’s hair.
While it might sound strange, it shouldn’t come as too much of
a surprise that men’s hair should be coarser than that of women. Hair
diameter also varies on average between races, making hair plugs on some
men look especially obvious.
- One human hair can support 3.5 ounces. That’s about
the weight of two full size candy bars, and with hundreds of thousands
of hairs on the human head, makes the tale of Rapunzel much more plausible.
- The fastest growing nail is on the middle finger.
And the nail on the middle finger of your dominant hand will grow the
fastest of all. Why is not entirely known, but nail growth is related to
the length of the finger, with the longest fingers growing nails the
fastest and shortest the slowest.
- There are as many hairs per square inch on your body as a
chimpanzee. Humans are not quite the naked apes that we’re made
out to be. We have lots of hair, but on most of us it’s not obvious as a
majority of the hairs are too fine or light to be seen.
- Blondes have more hair. They’re said to have more
fun, and they definitely have more hair. Hair color determines how dense
the hair on your head is. The average human has 100,000 hair follicles,
each of which is capable of producing 20 individual hairs during a
person’s lifetime. Blondes average 146,000 follicles while people with
black hair tend to have about 110,000 follicles. Those with brown hair
fit the average with 100,000 follicles and redheads have the least dense
hair, with about 86,000 follicles.
- Fingernails grow nearly 4 times faster than toenails.
If you notice that you’re trimming your fingernails much more frequently
than your toenails you’re not just imagining it. The nails that get the
most exposure and are used most frequently grow the fastest. On average,
nails on both the toes and fingers grow about one-tenth of an inch each
month.
- The lifespan of a human hair is 3 to 7 years on average.
While you quite a few hairs each day, your hairs actually have
a pretty long life providing they aren’t subject to any trauma. Your
hairs will likely get to see several different haircuts, styles, and
even possibly decades before they fall out on their own.
- You must lose over 50% of your scalp hairs before it is
apparent to anyone. You lose hundreds of hairs a day but you’ll
have to lose a lot more before you or anyone else will notice. Half of
the hairs on your pretty little head will have to disappear before your
impending baldness will become obvious to all those around you.
- Human hair is virtually indestructible. Aside from
it’s flammability, human hair decays at such a slow rate that it is
practically non-disintegrative. If you’ve ever wondered how your hair how
clogs up your pipes so quick consider this: hair cannot be destroyed by cold,
change of climate, water, or other natural forces and it is resistant to
many kinds of acids and corrosive chemicals.
Internal Organs
Though we may not give them much thought unless they’re bothering us, our
internal organs are what allow us to go on eating, breathing and walking
around. Here are some things to consider the next time you hear your stomach
growl.
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The largest internal organ is the small intestine.
Despite being called the smaller of the two intestines, your small
intestine is actually four times as long as the average adult is tall.
If it weren’t looped back and forth upon itself it wouldn’t fit inside
the abdominal cavity.
- The human heart creates enough pressure to squirt blood 30
feet. No wonder you can feel your heartbeat so easily. Pumping
blood through your body quickly and efficiently takes quite a bit of
pressure resulting in the strong contractions of the heart and the thick
walls of the ventricles which push blood to the body.
- The acid in your stomach is strong enough to dissolve
razorblades. While you certainly shouldn’t test the fortitude
of your stomach by eating a razorblade or any other metal object for
that matter, the acids that digest the food you eat aren’t to be taken lightly. Hydrochloric acid,
the type found in your stomach, is not only good at dissolving the pizza
you had for dinner but can also eat through many types of metal.
- The human body is estimated to have 60,000 miles of blood
vessels. To put that in perspective, the distance around the
earth is about 25,000 miles, making the distance your blood vessels
could travel if laid end to end more than two times around the earth.
- You get a new stomach lining every three to four days.
The mucus-like cells lining the walls of the stomach would soon dissolve
due to the strong digestive acids in your stomach if they weren’t
constantly replaced. Those with ulcers know how painful it can be when
stomach acid takes its toll on the lining of your stomach.
- The surface area of a human lung is equal to a tennis court.
In order to more efficiently oxygenate the blood, the lungs are
filled with thousands of branching bronchi and tiny, grape-like
alveoli. These are filled with microscopic capillaries which oxygen and carbon
dioxide. The large amount of surface area makes it easier for this
exchange to take place, and makes sure you stay properly oxygenated at
all times.
- Women’s hearts beat faster than men’s.The main
reason for this is simply that on average women tend to be smaller than
men and have less mass to pump blood to. But women’s and men’s hearts
can actually act quite differently, especially when experiencing trauma
like a heart attack, and many treatments that work for men must be adjusted
or changed entirely to work for women.
- Scientists have counted over 500 different liver functions.
You may not think much about your liver except after a long
night of drinking, but the liver is one of the body’s hardest working,
largest and busiest organs. Some of the functions your liver performs
are: production of bile, decomposition of red blood cells, plasma
protein synthesis, and detoxification.
- The aorta is nearly the diameter of a garden hose.
The average adult heart is about the size of two fists, making the size
of the aorta quite impressive. The artery needs to be so large as it is
the main supplier of rich, oxygenated blood to the rest of the body.
- Your left lung is smaller than your right lung to make room
for your heart. For most people, if they were asked to draw a
picture of what the lungs look like they would draw both looking roughly
the same size. While the lungs are fairly similar in size, the human
heart, though located fairly centrally, is tilted slightly to the left
making it take up more room on that side of the body and crowding out
that poor left lung.
- You could remove a large part of your internal organs and
survive. The human body may appear fragile but it’s possible to
survive even with the removal of the stomach, the spleen, 75 percent of
the liver, 80 percent of the intestines, one kidney, one lung, and
virtually every organ from the pelvic and groin area. You might not feel
too great, but the missing organs wouldn’t kill you.
- The adrenal glands change size throughout life. The
adrenal glands, lying right above the kidneys, are responsible for releasing stress
hormones like cortisol and adrenaline. In the seventh month of a fetus’
development, the glands are roughly the same size as the kidneys. At
birth, the glands have shrunk slightly and will continue to do so
throughout life. In fact, by the time a person reaches old age, the
glands are so small they can hardly be seen.
Bodily Functions
We may not always like to talk about them, but everyone has to deal with
bodily functions on a daily basis. These are a few facts about the
involuntary and sometimes unpleasant actions of our bodies.
- Sneezes regularly exceed 100 mph. There’s a good
reason why you can’t keep your eyes open when you sneeze–that sneeze is
rocketing out of your body at close to 100 mph. This is, of course, a
good reason to cover your mouth when you sneeze.
- Coughs clock in at about 60 mph. Viruses and colds
get spread around the office and the classroom quickly during cold and
flu season. With 60 mph coughs spraying germs far and wide, it’s no
wonder.
- Women blink twice as many times as men do. That’s a
lot of blinking every day. The average person, man or woman, blinks
about 13 times a minute.
- A full bladder is roughly the size of a soft ball.
No wonder you have to run to bathroom when you feel the call of the
wild. The average bladder holds about 400-800 cc of fluid but most
people will feel the urge to go long before that at 250 to 300 cc.
- Approximately 75% of human waste is made of water.
While we might typically think that urine is the liquid part of
human waste products, the truth is that what we consider solid waste is actually
mostly water as well. You should be thankful that most waste is fairly
water-filled, as drier harder stools are what cause constipation and are
much harder and sometimes painful to pass.
- Feet have 500,000 sweat glands and can produce more than a
pint of sweat a day. With that kind of sweat-producing power
it’s no wonder that your gym shoes have a stench that can peel paint.
Additionally, men usually have much more active sweat glands than women.
- During your lifetime, you will produce enough saliva to fill
two swimming pools. Saliva plays an important part in beginning
the digestive process and keeping the mouth lubricated, and your mouth
produces quite a bit of it on a daily basis.
- The average person expels flatulence 14 times each day.
Even if you’d like to think you’re too dignified to pass gas,
the reality is that almost everyone will at least a few times a day.
Digestion causes the body to release gases which can be painful if
trapped in the abdomen and not released.
- Earwax production is necessary for good ear health.
While many people find earwax to be disgusting, it’s actually a very
important part of your ear’s defense system. It protects the delicate
inner ear from bacteria, fungus, dirt and even insects. It also cleans
and lubricates the ear canal.
Sex and Reproduction
As taboo as it may be in some places, sex is an important part of human
life as a facet of relationships and the means to reproduce. Here are a few
things you might not have known.
- On any given day, sexual intercourse takes place 120 million
times on earth. Humans are a quickly proliferating species, and
with about 4% of the world’s population having sex on any given day,
it’s no wonder that birth rates continue to increase in many places all over the world.
- The largest cell in the human body is the female egg and the
smallest is the male sperm. While you can’t see skin cells or
muscle cells, the ovum is typically large enough to be seen with the
naked eye with a diameter of about a millimeter. The sperm cell, on the
other hand, is tiny, consisting of little more than nucleus.
- The three things pregnant women dream most of during their
first trimester are frogs, worms and potted plants. Pregnancy
hormones can cause mood swings, cravings and many other unexpected
changes. Oddly enough, hormones can often affect the types of dreams
women have and their vividness. The most common are these three types,
but many women also dream of water, giving birth or even have violent or
sexually charged dreams.
- Your teeth start growing 6 months before you are born.
While few babies are born with teeth in place, the teeth that
will eventually push through the gums of young children are formed long
before the child even leaves the womb. At 9 to 12 weeks the fetus starts
to form the teeth buds that will turn into baby teeth.
- Babies are always born with blue eyes. The color of
your eyes depends on the genes you get from your parents, but at birth
most babies appear to have blue eyes. The reason behind this is the
pigment melanin. The melanin in a newborn’s eyes often needs time after
birth to be fully deposited or to be darkened by exposure to ultraviolet
light, later revealing the baby’s true eye color.
- Babies are, pound for pound, stronger than an ox.
While a baby certainly couldn’t pull a covered wagon at its present
size, if the child were the size of an oxen it just might very well be
able to. Babies have especially strong and powerful legs for such tiny
creatures, so watch out for those kicks.
- One out of every 2,000 newborn infants has a tooth when they
are born. Nursing mothers may cringe at this fact. Sometimes
the tooth is a regular baby tooth that has already erupted and sometimes
it is an extra tooth that will fall out before the other set of choppers
comes in.
- A fetus acquires fingerprints at the age of three months.
When only a small fraction of the way through its development,
a fetus will have already developed one of the most unique human traits:
fingerprints. At only 6-13 weeks of development, the whorls of what will
be fingerprints have already developed. Oddly enough, those fingerprints
will not change throughout the person’s life and will be one of the last
things to disappear after death.
- Every human spent about half an hour as a single cell.
All life has to begin somewhere, and even the largest humans
spent a short part of their lives as a single celled organism when sperm
and egg cells first combine. Shortly afterward, the cells begin rapidly
dividing and begin forming the components of a tiny embryo.
- Most men have erections every hour to hour and a half during
sleep. Most people’s bodies and minds are much more active when
they’re sleeping than they think. The combination of blood circulation
and testosterone production can cause erections during sleep and they’re
often a normal and necessary part of REM sleep.
Senses
The primary means by which we interact with the world around us is
through our senses. Here are some interesting facts about these five sensory
abilities.
- After eating too much, your hearing is less sharp.
If you’re heading to a concert or a musical after a big meal you may be
doing yourself a disservice. Try eating a smaller meal if you need to
keep your hearing pitch perfect.
- About one third of the human race has 20-20 vision.
Glasses and contact wearers are hardly alone in a world where two thirds
of the population have less than perfect vision. The amount of people
with perfect vision decreases further as they age.
- If saliva cannot dissolve something, you cannot taste it.
In order for foods, or anything else, to have a taste,
chemicals from the substance must be dissolved by saliva. If you don’t
believe it, try drying off your tongue before tasting something.
- Women are born better smellers than men and remain better
smellers over life.
Studies have shown that women are more able to correctly pinpoint just what a
smell is. Women were better able to identify citrus, vanilla, cinnamon
and coffee smells. While women are overall better smellers, there is an
unfortunate 2% of the population with no sense of smell at all.
- Your nose can remember 50,000 different scents.
While a bloodhound’s nose may be a million times more sensitive than a
human’s, that doesn’t mean that the human sense of smell is useless.
Humans can identify a wide variety of scents and many are strongly tied
to memories.
- Even small noises cause the pupils of the eyes to dilate.
It is believed that this is why surgeons, watchmakers and others who
perform delicate manual operations are so bothered by uninvited noise.
The sound causes their pupils to change focus and blur their vision,
making it harder to do their job well.
- Everyone has a unique smell, except for identical twins.
Newborns are able to recognize the smell of their mothers and
many of us can pinpoint the smell of our significant others and those we
are close to. Part of that smell is determined by genetics, but it’s
also largely do to environment, diet and personal hygiene products that
create a unique chemistry for each person.
Aging and Death
From the very young to the very old, aging is a necessary and unavoidable
part of life. Learn about the process with these interesting, if somewhat
strange facts.
- The ashes of a cremated person average about 9 pounds.
A big part of what gives the human body weight is the water
trapped in our cells. Once cremated, that water and a majority of our
tissues are destroyed, leaving little behind.
- Nails and hair do not continue to grow after we die.
They do appear longer when we die, however, as the skin dehydrates and
pulls back from the nail beds and scalp.
- By the age of 60, most people will have lost about half
their taste buds. Perhaps you shouldn’t trust your grandma’s
cooking as much as you do. Older individuals tend to lose their ability
to taste, and many find that they need much more intense flavoring in
order to be able to fully appreciate a dish.
- Your eyes are always the same size from birth but your nose
and ears never stop growing. When babies look up at you with
those big eyes, they’re the same size that they’ll be carrying around in
their bodies for the rest of their lives. Their ears and nose, however,
will grow throughout their lives and research has shown that growth
peaks in seven year cycles.
- By 60 years of age, 60-percent of men and 40-percent of
women will snore. If you’ve ever been kept awake by a snoring
loved one you know the sound can be deafening. Normal snores average
around 60 decibels, the noise level of normal speech, intense snores can
reach more than 80 decibels, the approximate level caused by a
jackhammer breaking up concrete.
- A baby’s head is one-quarter of it’s total length, but by
age 25 will only be one-eighth of its total length. As it turns
out, our adorably oversized baby heads won’t change size as drastically
as the rest of our body. The legs and torso will lengthen, but the head
won’t get much longer.
Disease and Injury
Most of us will get injured or sick at some point in our lives. Here are
some facts on how the human body reacts to the stresses and dangers from the
outside world.
- Monday is the day of the week when the risk of heart attack
is greatest. Yet another reason to loathe Mondays! A
ten year study in Scotland found that 20% more people die of heart attacks on Mondays
than any other day of the week. Researchers theorize that it’s a
combination of too much fun over the weekend with the stress of going
back to work that causes the increase.
- Humans can make do longer without food than sleep.
While you might feel better prepared to stay up all night partying than
to give up eating, that feeling will be relatively short lived. Provided
there is water, the average human could survive a month to two months
without food depending on their body fat and other factors. Sleep
deprived people, however, start experiencing radical personality and
psychological changes after only a few sleepless days. The longest
recorded time anyone has ever gone without sleep is 11 days, at the end
of which the experimenter was awake, but stumbled over words, hallucinated and frequently forgot
what he was doing.
- A simple, moderately severe sunburn damages the blood
vessels extensively. How extensively? Studies have shown that
it can take four to fifteen months for them to return to their normal
condition. Consider that the next time you’re feeling too lazy to apply
sunscreen before heading outside.
- Over 90% of diseases are caused or complicated by stress.
That high stress job you have could be doing more than just
wearing you down each day. It could also be increasing your chances of
having a variety of serious medical conditions like depression, high blood pressure and heart disease.
- A human head remains conscious for about 15 to 20 seconds
after it is been decapitated. While it might be gross to think
about, the blood in the head may be enough to keep someone alive and
conscious for a few seconds after the head has been separated from the
body, though reports as to the
accuracy of this are widely varying.
Muscles and Bones
Muscles and Bones provide the framework for our bodies and allow us to
jump, run or just lie on the couch. Here are a few facts to ponder the next
time you’re lying around.
- It takes 17 muscles to smile and 43 to frown.
Unless you’re trying to give your face a bit of a workout, smiling is a
much easier option for most of us. Anyone who’s ever scowled, squinted
or frowned for a long period of time knows how it tires out the face
which doesn’t do a thing to improve your mood.
- Babies are born with 300 bones, but by adulthood the number
is reduced to 206. The reason for this is that many of the
bones of children are composed of smaller component bones that are not yet fused like those in the skull. This
makes it easier for the baby to pass through the birth canal. The bones
harden and fuse as the children grow.
- We are about 1 cm taller in the morning than in the evening.
The cartilage between our bones gets compressed by standing,
sitting and other daily activities as the day goes on, making us just a
little shorter at the end of the day than at the beginning.
- The strongest muscle in the human body is the tongue.
While you may not be able to bench press much with your tongue,
it is in fact the strongest muscle in your body in proportion to its
size. If you think about it, every time you eat, swallow or talk you use
your tongue, ensuring it gets quite a workout throughout the day.
- The hardest bone in the human body is the jawbone.
The next time someone suggests you take it on the chin, you might be
well advised to take their advice as the jawbone is one of the most
durable and hard to break bones in the body.
- You use 200 muscles to take one step. Depending on
how you divide up muscle groups, just to take a single step you use
somewhere in the neighborhood of 200 muscles. That’s a lot of work for
the muscles considering most of us take about 10,000 steps a day.
- The tooth is the only part of the human body that can’t
repair itself. If you’ve ever chipped a tooth you know just how
sadly true this one is. The outer layer of the tooth is enamel which is
not a living tissue. Since it’s not alive, it can’t repair itself,
leaving your dentist to do the work instead.
- It takes twice as long to lose new muscle if you stop
working out than it did to gain it. Lazy people out there
shouldn’t use this as motivation to not work out, however. It’s
relatively easy to build new muscle tissue and get your muscles in
shape, so if anything, this fact should be motivation to get off the
couch and get moving.
- Bone is stronger than some steel. This doesn’t mean
your bones can’t break of course, as they are much less dense than
steel. Bone has been found to have a tensile strength of 20,000 psi
while steel is much higher at 70,000 psi. Steel is much heavier than
bone, however, and pound for pound bone is the stronger material.
- The feet account for one quarter of all the human body’s
bones. You may not give your feet much thought but they are
home to more bones than any other part of your body. How many? Of the
two hundred or so bones in the body, the feet contain a whopping 52 of
them.
Microscopic Level
Much of what takes place in our bodies happens at a level that we simply
can’t see with the naked eye. These facts will show you that sometimes that
might be for the best.
- About 32 million bacteria call every inch of your skin home.
Germaphobes don’t need to worry however, as a majority of these
are entirely harmless and some are even helpful in maintaining a healthy
body.
- Humans shed and regrow outer skin cells about every 27 days.
Skin protects your delicate internal organs from the elements
and as such, dries and flakes off completely about once a month so that
it can maintain its strength. Chances are that last month’s skin is
still hanging around your house in the form of the dust on your
bookshelf or under the couch.
- Three hundred million cells die in the human body every
minute. While that sounds like a lot, it’s really just a small
fraction of the cells that are in the human body.
Estimates have placed the total number of cells in the body at 10-50 trillion so you can
afford to lose a few hundred million without a hitch.
- Humans shed about 600,000 particles of skin every hour.
You may not think much about losing skin if yours isn’t dry or
flaky or peeling from a sunburn, but your skin is constantly renewing
itself and shedding dead cells.
- Every day an adult body produces 300 billion new cells.
Your body not only needs energy to keep your organs up and
running but also to constantly repair and build new cells to form the
building blocks of your body itself.
- Every tongue print is unique. If you’re planning on
committing a crime, don’t think you’ll get away with leaving a tongue
print behind. Each tongue is different and yours could be unique enough
to finger you as the culprit.
- Your body has enough iron in it to make a nail 3 inches
long. Anyone who has ever tasted blood knows that it has a
slightly metallic taste. This is due to the high levels of iron in the
blood. If you were to take all of this iron out of the body, you’d have
enough to make a small nail and very severe anemia.
- The most common blood type in the world is Type O.
Blood banks find it valuable as it can be given to those with both type
A and B blood. The rarest blood type, A-H or Bombay blood due to the
location of its discovery, has been found in less than hundred people
since it was discovered.
- Human lips have a reddish color because of the great
concentration of tiny capillaries just below the skin. The
blood in these capillaries is normally highly oxygenated and therefore
quite red. This explains why the lips appear pale when a person is
anemic or has lost a great deal of blood. It also explains why the lips
turn blue in very cold weather. Cold causes the capillaries to
constrict, and the blood loses oxygen and changes to a darker color.
Miscellaneous
Here are a few things you might not have known about all different parts
of your anatomy.
- The colder the room you sleep in, the better the chances are
that you’ll have a bad dream. It isn’t entirely clear to
scientists why this is the case, but if you are opposed to having
nightmares you might want to keep yourself a little toastier at night.
- Tears and mucus contain an enzyme (lysozyme) that breaks
down the cell wall of many bacteria. This is to your advantage,
as the mucus that lines your nose and throat, as well as the tears that
wet your eyes are helping to prevent bacteria from infecting those areas
and making you sick.
- Your body gives off enough heat in 30 minutes to bring half
a gallon of water to a boil. If you’ve seen the Matrix you are
aware of the energy potentially generated by the human body. Our bodies
expend a large amount of calories keeping us at a steady 98.6 degrees,
enough to boil water or even cook pasta.
- Your ears secrete more earwax when you are afraid than when
you aren’t. The chemicals and hormones released when you are
afraid could be having unseen effects on your body in the form of
earwax. Studies have suggested that fear causes the ears to produce more
of the sticky substance, though the reasons are not yet clear.
- It is not possible to tickle yourself. Even the
most ticklish among us do not have the ability to tickle ourselves. The
reason behind this is that your brain predicts the tickle from information it
already has, like how your fingers are moving. Because it knows and can
feel where the tickle is coming from, your brain doesn’t respond in the
same way as it would if someone else was doing the tickling.
- The width of your armspan stretched out is the length of
your whole body. While not exact down to the last millimeter,
your armspan is a pretty good estimator of your height.
- Humans are the only animals to produce emotional tears.
In the animal world, humans are the biggest crybabies, being
the only animals who cry because they’ve had a bad day, lost a loved
one, or just don’t feel good.
- Right-handed people live, on average, nine years longer than
left-handed people do. This doesn’t have a genetic basis, but
is largely due to the fact that a majority of the machines and tools we
use on a daily basis are designed for those who are right handed, making
them somewhat dangerous for lefties to use and resulting in thousands of
accidents and deaths each year.
- Women burn fat more slowly than men, by a rate of about 50
calories a day. Most men have a much easier time burning fat
than women. Women, because of their reproductive role, generally require
a higher basic body fat proportion than men, and as a result their
bodies don’t get rid of excess fat at the same rate as men.
- Koalas and primates are the only animals with unique
fingerprints. Humans, apes and koalas are unique in the animal
kingdom due to the tiny prints on the fingers of their hands. Studies on
primates have suggested that even cloned individuals have unique fingerprints.
- The indentation in the middle of the area between the nose
and the upper lip has a name. It is called the philtrum.
Scientists have yet to figure out what purpose this indentation serves,
though the ancient Greeks thought it to be one of the most erogenous
places on the body.
Reference:
Laun Christina, "100 weird facts about the human body," Bootstrapper, February 27, 2008. Laud's article is no long active.
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