Top 100 Unknown Facts About the Human Body by KnewThis.com
100 Unknown Facts About the Human Body
"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
"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."
1. 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.
2. 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.
3. 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.
4. 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.
5. 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.
6. 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.
7. 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.
8. 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.
9. 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.
10. 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."
11. 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.
12. 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.
13. 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.
14. 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.
15. 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.
16. 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.
17. 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.
18. 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.
19. 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.
20. 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.
21. Human hair is virtually indestructible.
Aside from its’ flammability, human hair decays at such a slow rate that it is
practically non-disintegrative. If you’ve ever wondered how your 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."
22. 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.
23. 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.
24. 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.
25. 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.
26. 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.
27. 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.
28. 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.
29. 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.
30. 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 as large as it
is the main supplier of rich, oxygenated blood to the rest of the body.
31. 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.
32. 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.
33. 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 foetus’ 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
"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."
34. 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.
35. 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.
36. 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.
37. 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.
38. 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.
39. 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.
40. 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.
41. 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.
42. 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 defence 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."
43. 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.
44. 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.
45. 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.
46. 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.
47. 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 new-born’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.
48. 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.
49. One out of every 2,000 new-born 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.
50. 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.
51. 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.
52. 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."
53. 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.
54. 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.
55. 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.
56. 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.
57. Your nose can remember 50,000 different
scents. While a bloodhounds’ nose may be a million times more sensitive
than a humans’, 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.
58. 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.
59. Everyone has a unique smell, except for
identical twins. New-borns 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 due 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."
60. 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.
61. 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.
62. 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 flavouring in
order to be able to fully appreciate a dish.
63. 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.
64. 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.
65. A baby’s head is one-quarter of its 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."
66. 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.
67. 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.
68. 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.
69. 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.
70. 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."
71. 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.
72. 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.
73. 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.
74. 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.
75. 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.
76. 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 neighbourhood of 200 muscles. That’s a lot of work for the
muscles considering most of us take about 10,000 steps a day.
77. 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 its’ not alive, it can’t’ repair itself, leaving your
dentist to do the work instead.
78. 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.
79. 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.
80. 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."
81. 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.
82. 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.
83. 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.
84. 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.
85. 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.
86. 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.
87. 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.
88. 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.
89. 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."
90. 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.
91. 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.
92. 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.
93. 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.
94. 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.
95. The width of your arm span stretched out is
the length of your whole body. While not exact down to the last millimeter,
your arm span is a pretty good estimator of your height.
96. Humans are the only animals to produce
emotional tears. In the animal world, humans are the biggest cry-babies,
being the only animals who cry because they’ve had a bad day, lost a loved one,
or just don’t feel good.
97. 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.
98. 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.
99. 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.
100. 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.
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