ANATOMY FACTS

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The average human blinks their eyes 6,205,000 times each year.
The length of the finger dictates how fast the fingernail grows. Therefore, the nail on your middle finger grows the fastest, and on average, your ingrowntoenails twice as slow as your fingernails.
The average human will shed 40 pounds of skin in a lifetime.
The B-complex vitamins will make your urine fluorescent yellow. (Not just yellow, but very fluorescent!). It's just excess that wasn't used up and is flushed out of your body.
Nerve impulses to and from the brain travel as fast as 170 miles (274 km) per hour.
During a 24-hour period, the average human will breathe 23,040 times.
The average person falls asleep in seven minutes.
15 million blood cells are destroyed in thehuman body every second.
Only 1 person in 2 billion will live to be 116 or older.
The average life of a taste bud is 10 days.
The average cough comes out of your mouth at 60 miles (24 km) per hour.
Every year about 98% of the atoms in your body are replaced.
The bones of movable joints are covered with a clear, thick, lubricating liquid called the synovial fluid, which acts like oil to make the joints work smoothly. If it weren't for this fluid, you would squeak when you walk.
When a person is "shocked" the sensation is actually one of blood rushing to brain.
Overuse of moisturizers actually inhibits the body’s natural lipid production. Lipids are responsible for depositing fatty secretions to the skin making it smooth and silky feeling.
The bones in children's hands are composed primarily of cartilage. It is not until the onset of puberty, and the subsequent hormonal changes, which allows for the fusion of bones to be possible.
There are chemicals in sperm, which when absorbed into the blood stream have therapeutic effects.
A person remains conscious for eight seconds after being decapitated.
"Passion purpura" is the medical term for a hickey.
A study has shown that musicians' brains contained 130% more nerve cells in their auditory cortex, a part of the brain linked to hearing, than non-musicians. Furthermore, the level of brain activity in professional musicians was shown to be 102% higher than normal, while the brains of amateur musicians were 37% more active than average.
American Indians lack an enzymes in their system, which promotes the oxidation of alcohol so that it may be broken down and passed through the system.
Intelligent people have more zincand copper in their hair.
According to researcher Andrews McMeel, sniffing crayons (one of the 20 most recognizable scents) has been shown to lower blood pressure.
Banging your head against a wall uses 150 calories an hour.
On average, a human being will have sex more than 3,000 times and spend two weeks kissing in their lifetime.
In the course of an average lifetime you will, while sleeping, eat 70 assorted insects and 10 spiders.
Like fingerprints, everyone's tongue print is different.
Because of the preservatives in our food, the human body actually takes longer to decompose.
You're born with 300 bones, but when you get to be an adult, you only have 206. (They fuse together such as the parietal, occipital of the skull.)
It has been said that in one year the average person breathes in two grams of solid pollution, eats twelve pounds of Food Additives, their own body weight in sugar and a gallon of pesticides!
Wearing headphones for just an hour will increase bacteria in your ear by 700 times.
It is impossible to lick your elbow (But you will try).
The tongue can create a pressure on the roof of the mouth equivalent to the weight of two double decker busses.
If you sneeze too hard, you can fracture a rib. If you try to suppress a sneeze, you can rupture a blood vessel in your head or neck and die. If you keep your eyes open by force, they will pop out.
Conception occurs more often in December than any other month.
Your Body contains about 96,558 km (59,962 miles) of blood vessels. If you took someone's blood vessels and laid them end-to-end they'd go twice round the world.
The strongest muscle in the body is the tongue.
When you sneeze, your whole body stops - even your heart!
Human fingertips are so sensitive that they can feel an object move even if it stirs a thousandth of a millimeter.
A rope made from 1000 human hairs could lift a well-built man.
If you didn't cut your fingernails for a year, they would be 2.5 cm long.
Women blink nearly twice as much as men.
The average adult stands 0.4 inch (1 cm) taller in the morning than the evening, because the cartilage in the spinecompresses during the day.
It only takes 7 pounds of pressure to rip your ear off.
Ingrown toe nails are genetic.
Tongue rolling is not genetic.
Our eyes are always the same size from birth, but our nose and ears never stop growing.
Inflammation of the bladder can be caused by nylon underwear!
When you blush the insides of your stomach turn red.
The distance between your wrist and elbow is the length of your foot.
If you stretch your arms as far as they can reach to the sides that length is as long as you are tall.
Every time you lick a stamp, you're consuming 1/10 of a calorie.
Your stomach has to produce a new layer of mucus every two weeks otherwise it will digest itself.
When you die you expel 32 quarts of gas.
In one year the average human swallows 7 spiders in their sleep.
Barbie's measurements if she were life size: 39-23-33.
Babies are born without kneecaps. They don't appear until the child reaches 2-6 years of age.
Nutmeg is extremely poisonous if injected intravenously.
One drop of blood contains a half a drop of plasma, 5 MILLION Red Blood Cells, 10 Thousand White Blood Cells and 250 Thousand Platelets.
You have thousands of miles of blood vessels in your body. "Bill Nye the Science Guy" claims that you could wrap your blood vessels around the equator TWICE!
Keep your heart healthy...it's going to have to beat about 3 BILLION times during your lifetime!
A person's sense of smell is the first to go.
A sneeze leaves your mouth at over 600 mph.
The flu was first described by Hippocrates in 412 BC
The human body contains about 10 gallons for water making up 60% of body weight.
Your body creates as much as two quarts of saliva daily.
You're more likely to catch a cold from a person by shaking their hand than from their sneezes.
The human brain weighs about 3 pounds, but uses 20% of one's blood and oxygen.
Plaque begins reforming 6 hours after brushing your teeth.
If your body temperature was 86 degrees, you could live to be 200.
Cold showers actually increase sexual arousal.
A Swiss scientist named A. E. Fick invented contact lenses in 1887.
There is enough phosphorous inside the human body to make about 250 match heads.
Doctors in ancient China were paid when patients were healthy, not sick.
The human head weighs eight pounds.
The human hand has 27 bones.
The human foot has 26 bones.
Kotex was first manufactured as bandages during World War I.
Humans and dolphins are the only species that have sex for pleasure.
If you fart consistently for 6 years and 9 months, enough gas is produced to create the energy of an atomic bomb.
Dentists have recommended that a toothbrush be kept at least 6 feet away from a toilet to avoid airborne particles resulting from the flush.
The liquid inside young coconuts can be used as substitute for blood plasma.
You burn more calories sleeping than you do watching television.
Apples, not caffeine, are more efficient at waking you up in the morning.
The part of the scallop eaten as food is the adductor muscle used to open and close their shell
The thing dangling in the back of your throat is called the uvula
The word Penis is Latin for tail.
The plasma in blood has the same percentage of salt as seawater.
More than 75 different kinds of bacteria are found in human feces.
Your brain is 80% water.
Albert Einstein's brain was kept in two mason jars in Kansas long after his body was cremated.
Someone without a sense of smell suffers from anosmia and can therefore be called anosmiac.
Eskimos use refrigerators to keep food from freezing.
The term "spa" is derived from a town in Belgium of the same name, known for its baths and mineral springs.
There is no medical name for boogers.
The white part of your fingernail is called the lunula.
Human nails and hair do not grow after death. After you die, your body starts to dry out creating the illusion that your hair and nails are still growing after death.
Human eyes have two types of light-sensitive cells in the retina called rods and cones. Rods work best in dim light and can detect motion. Cones are used in bright light to detect color and details.
On average, 100 people choke to death on ballpoint pens every year.
Only one person in two billion will live to be 116 or older.
The world's termites outweigh the world's humans 10 to 1.
It's impossible to sneeze with your eyes open.
To "testify" was based on men in the Roman court swearing to a statement made by swearing on their testicles.
Honey is the only food that doesn't spoil?
If you yelled for 8 years, 7 months and 6 days, you will have produced enough sound energy to heat one cup of coffee.
On average, people fear spiders more than they do death.
Right-handed people live, on average, nine years longer than left-handed people do.
The human heart creates enough pressure when it pumps out to the body to squirt blood 30 feet.
Your stomach has to produce a new layer of mucus every two weeks or it will digest itself.
The average person's left hand does 56% of the typing.
There are more chickens than people in the world.
If you sneeze, hiccup and pass gas all at the same time, you explode!!!
The average person takes 12-18 breaths per minute.
The right lung takes in more air than the left.
The human body has 45 miles of nerves.
The average person's field of vision is 180 degrees.
Your brain stops growing when you are about 15 years old.
There are over 650 muscles in your body. A smile uses 17 muscles & a frown uses 43!
The eye muscle is the fastest reacting muscle of the whole body. It contracts in less than 1/100th of a second.
The longest muscle in your body is the sartorius.
The smallest muscle of the skeleton is the stapedius, which measures 1/20th of an inch. It is the activator of the stirrup that sends vibrations from the eardrum to the inner ear.
The largest muscle is the latissimus dorsi. This is the flat muscle of the back that operates during arm movement.
The strongest muscle in your body is the gluteus maximus. Our buttock is also the least sensitive part of our body.
Your tongue is also considered one of the strongest muscles in your body?
Over 2500 left handed people a year are killed from using products made for right-handed people!
You'll eat about 35,000 cookies in a lifetime!
Ketchup was once sold as a patent medicine known as Dr. Miles' Compound Extract of Tomato.
St. Paul, Minnesota was originally called Pigs Eye after a man who ran a saloon there.
Ancient Romans smeared pigeon droppings in their hair to bleach it.
The Cherokee addressed poison ivy as "my friend" to keep it from attacking.
To make their hands look younger, women once covered them with the skin of a chicken.
The human brain uses as much energy as a 10-watt light bulb.
More people are killed by donkeys than in airplane crashes.
The loudest recorded snore is 87.5 decibels.
The human brain uses as much energy as a 10-watt light bulb.
Toilets injure 40,000 Americans each year.
You speak about 4,800 words per day.
We spend about 6 months of our lives waiting at red lights.
You breathe 13 pints of air every minute.
The human eye can see 7,000,000 colors.
By the time you're 75 years old, you will have spent 23 years sleeping.
Humans breathe through one nostril at a time, each for 2 to 4 hours while the other rests.
The chances of death from a shark are 1 in 300,000,000 vs. 1 in 6,000,000 for a bee.
A cockroach can live nine days without its head before it starves to death.
The Neanderthal's brain was bigger than your brain.
The largest recorded tumor weighed in at 303 pounds!
The feet contain 1/4 of all bones in the human body.
13 people die every year from falling vending machines.
A pack-a-day smoker will loose approx. 2 teeth every 10 years.
Many Japanese hospitals do not have a fourth floor because 4 is an unlucky number in Japan (The Japanese word for "four" sounds like the word for "death".)
The human brain weighs about 3 pounds, but uses 20% of one's blood and oxygen.
The human hand contains an average of 1,300 nerve endings per square inch.
If one identical twin grows up without a given tooth coming in, the second identical twin will usually also grow up without the tooth.
If one were to unravel the entire human alimentary canal (esophagus, stomach, large and small intestines), it would reach the height of a three-story building
If someone is "androphobic," they have an extreme, irrational fear of men.
If the roof of your mouth is narrow, you are more prone to snore since you are not getting enough oxygen through your nose.
We think we cannot see at night. But given enough time to adjust, the human eye can, for a time, see almost as well as an owl's. Ultimately, as the amount of light decreases, an owl detects shapes after a human no longer can.
When astronauts remain weightless in space for prolonged periods, scientists have discovered their bones lose a measurable amount of weight and thickness. This means that weightlessness actually cause human beings to shrink.
The human foot has 26 bones, 33 joints, 107 ligaments, 19 muscles and tendons. The 52 bones in your feet make up about 25 percent of all the bones in your body.
When the female embryo is only six weeks old, it makes preparations for her motherhood by developing egg cells for future offspring. (When the baby girl is born, each of her ovaries carries about a million egg cells, all she will ever have)
The human hand contains an average of 1,300 nerve endings per square inch.
Over the many centuries of living in the Arctic, Eskimos' bodies have adapted to the cold. Eskimos tend to be short and squat, which brings their arms and legs closer to the heart, so there is less danger of freezing. Extra fat around the torso protects their internal organs from the cold. The metabolism of Eskimos is also set a little higher than other people's. As a result, they burn their food faster to stay warm. Their veins and arteries are also arranged to carry more warming blood to their hands.
When we smile broadly, we use seventeen muscles.
The human hand has 27 bones and 35 muscles.
Pain from any injury or illness is always registered by the brain. Yet, curiously, the brain tissue itself is immune to pain; it contains none of the specialized receptor cells that sense pain in other parts of the body. The pain associated with brain tumors does not arise from brain cells but from the pressure created by a growing tumor or tissues outside the brain.
When you have a black eye, you have a bilateral periorbital hematoma.
The human heart beats about 70 times per minute, the shrew's 600 times a minute, a hummingbird's heart can beat up to 1,300 times per minute. By comparison, the blue whale, the largest mammal in the world has a heart that weighs 1,300 lbs and beats only about 10 times per minute. .
Parts of the human anatomy have evolved into common expressions in American speech. A few examples include: A good head on his shoulders; the shoe's on the other foot; a heart of gold; chip on his shoulder; a nose for crime; turn the other cheek; a pain in the neck; rub someone's nose in it; a price on his head; apple of his eye; snap his head off; put your foot down; shoulder to the wheel; you're pulling my leg; stick your neck out; twist around your little finger; heart-to-heart talk; keep your head above water. The list goes on and on.
While 7 men in 100 have some form of colorblindness, only 1 woman in 1,000 suffers from it. The most common form of color blindness is a red-green deficiency.
The human heart creates enough pressure when it pumps out to the body to squirt blood 30 feet.
People dream an average of five times a night, and each subsequent dream is longer than the one preceding it. The first dream of the evening is about 10 minutes long, and the last dream is about 45 minutes.
While examining urine, German chemist Hennig Brand discovered phosphorus.
The human heart rests between beats. In an average lifetime of 70 years, the total resting time is estimated to be about 40 years.
People lose more than hair as they grow old. By the age of 70, half of your taste buds will be gone.
While reading a page of print, the eyes do not move continually across the page. They move in a series of jumps, called "fixations," from one clump of words to the next.
The human sense of smell is so keen that it can detect the odors of certain substances even when they are diluted to 1 part to 30 billion.
Per "Longevity" magazine, a number of plastic surgeons now require their prospective patients to undergo a series of psychological tests to determine if they will become emotionally unstable, excessively anxious, or threatening to the doctor following their cosmetic surgery.
Whispering is more wearing on your voice than a normal speaking tone. Whispering and shouting stretch the vocal cords.
The human stomach lining replaces itself every three days.
Per 1999 medical data, an alarming 2 million people are hospitalized and as many as 140,000 die each year from side effects or reactions to prescription drugs.
Women blink nearly twice as much as men.
The human tongue tastes bitter things with the taste buds toward the back. Salty and pungent flavors are detected at the middle of the tongue, sweet flavors at the tip.
Permanent hearing loss can result from prolonged exposure to sounds at 85 decibels (0 decibels is the threshold for hearing). For comparison, a busy street corner is about 80 decibels, a subway train from 20 feet is 100 decibels, a jet plane from 500 feet is 110 decibels and loud thunder is 120 decibels. A rock band amplified at close range is 140 decibels, which is 100 trillion times threshold and more than 100,000 times as loud as the level that will produce permanent hearing loss.
The hydrochloric acid of the human digestive process is so strong a corrosive that it easily can eat its way through a cotton handkerchief, and even through the iron of an automobile body. Yet, it doesn't endanger the stomach's sticky mucus walls.
Perspiration is odorless. It is the bacteria on the skin that creates an odor
Pigs, dogs, and some other animals can taste water, but people cannot. Humans don't actually taste the water, they taste the chemicals and impurities in the water.
Women navigate by landmarks and visual memories. Men navigate by direction and distance, and tend to be better at reading maps.
Women reject heart transplants more often than men.
The indentation in the middle area between the nose and the upper lip is called the Philtrum. Ancient Greeks considered this to be one of the body's most erogenous zones.
You blink every 2-10 seconds. As you focus on each word in this sentence, your eyes swing back and forth 100 times a second, and every second, the retina performs 10 billion computer-like calculations.
The Ketchua Indians of the Andes Mountains in South America have 2 to 3 more quarts of blood in their bodies than people who live at lower elevations.
Plants in the mint family have been used for centuries by people as anti-spasmodics. Current studies suggest that ingesting peppermint oil (available in capsule form) helps relieve internal gas and bloating.
You can't kill yourself by holding your breath. At worst, you would lose consciousness and the lungs would start to breath automatically.
The kidney consists of over 1 million little tubes, and the total length of the tubes in both kidneys runs to about forty miles.
Quaaludes were first developed to fight malaria. .
You will get fewer cavities if you eat a bag of candy in one sitting and then brush your teeth than if you slowly eat the candy a piece at a time all day
The knee is the most easily injured of all the joints in the body and the most frequently treated area by orthopedic surgeons, according to a report from the American Academy of Orthopaedic Surgeons. More than 6 million people visit an orthopedic surgeon each year for a knee problem, the report said. Hospital emergency rooms log 1.4 million visits per year for knee problems.
Researchers claim that the color light-green is effective in relieving the feelings of homesickness.
Your brain is more active sleeping than it is watching TV
The largest cell in the human body is the female ovum, or egg cell. It is about 1/180 inch in diameter. The smallest cell in the human body is the male sperm. It takes about 175,000 sperm cells to weigh as much as a single egg cell.
Researchers claim that, on the average, a woman is three times more sensitive than a man to noises while sleeping.
Zoonoses are animal diseases communicable to man.
The lens of the eye continues to grow throughout a person's life.
Researchers have discovered that events such as pleasant family celebrations or evenings with friends boost the immune system for the following two days. Unpleasant moments had the opposite effect: negative events, such as being criticized at work, weakened the immune function for one day afterward.
The little lump of flesh just forward of your ear canal, right next to your temple, is called a tragus.
Researchers looked at more than 400 non-food choking deaths in children over a 20-year period, and found that most were caused by balloons (29 percent) and balls and marbles (19 percent). More older children died from balloons than did toddlers.
The liver is a gland, not an organ.
Scientists estimate that there are 3 million to 4 million genes in each human cell, and yet they have been able to identify one particular gene among those millions, produce and image of that gene, and examine it for abnormalities.
The liver stretches across almost the width of the body, occupying a space about the size of a football. It weighs more than 3 lbs.
Scientists estimate that they could fill a 1,000-volume encyclopedia with the coded instructions in the DNA of a single human cell if the instructions could be translated to English.

The longest muscle in the human body is the sartorius. This narrow muscle of the thigh passes obliquely across the front of the thigh and helps rotate the leg to the position assumed in sitting cross-legged. Its name is a derivation of the adjective "sartorial," a reference to what was the traditional cross-legged position of tailors (or "sartors") at work.
Scientists have found chocolate has a chemical that helps counteract depression.
Scientists have found that the skin of the armpits can harbor up to 516,000 bacteria per square inch, while drier areas, such as the forearm, have only about 13,000 bacteria per square inch.
The lungs of an average adult, unfolded and flattened out, would cover an area the size of a tennis court.
The mineral calcium prevents or helps alleviate muscle cramps.
Scientists say that people who sleep less than average (less than 6 hours a night) are more organized and efficient than everybody else.
The mineral content, porosity, and general makeup of human bone is nearly identical to some species of South Pacific coral. The two are so alike that plastic surgeons are using the coral to replace lost human bone in facial reconstructions.
Seeing another person yawn makes it likely that you will yawn yourself. Thinking about, even reading about yawning can set you off. People with mental disorders such as psychoses rarely yawn.
The mouth produces a quart of saliva a day.
Senior citizens are at greater risk for dehydration than younger people because their bodies are less effective at letting them know when they need water.
The National Institute of Mental Health places fear of flying (aerophobia), second only to fear of public speaking.
Sight accounts for 90 to 95 percent of all sensory perceptions.
The nose cleans, warms, and humidifies over 500 cubic feet of air every day
Sixty thousand miles of vessels carry blood to every part of your body
The number of centenarians – 100 years and older – has more than doubled since 1980 to about 50,000. Four in five were women.
Small animals like bats and shrews consume up to one and one half times their body weight in food every day. For an adult male, this would be like eating 1,000 quarter-pound cheeseburgers a day, every day; or about 50 Thanksgiving dinners a day.
The older a person gets the less sleep he/she requires. A child should get from 8 to 10 hours a night. An elderly adult can do well with 4 to 6 hours.
Snacking accounts for 15 to 20 percent of Americans' daily caloric intake.
The oldest way to lose weight is fasting --- the ultimate diet.
Someone who speaks through clenched teeth is called a dentiloquist.
The only part of the human body that has no blood supply is the cornea. It takes its oxygen directly from the air.
Someone with an irrational fear of meat is "carnophobic."
Sounds too low for human beings to hear are called infrasonic.
The palms of the hands and soles of the feet contain more sweat glands than any other part of the body.
The pituitary gland - responsible for producing the hormone that regulates growth - is only the size of a pea and weighs little more than a small paper clip.
Soviet doctors have noticed a tendency by people living near Chernobyl to blame any and all ills on radiation — an affliction they are calling "radiophobia."
The pupil of the eye expands as much as 45 percent when a person looks at something pleasing.
Statistics based on more than a half-million births occurring in New York City hospitals between 1948 and 1957 show a significantly greater number of births taking place during the waning moon than during a waxing moon.
The right lung takes in more air than the left.
Stress may be good for people. Rockefeller University scientists have determined that an acute episode of stress boosts immunity, offering better protection against infection. The fact that people don’t usually catch a cold until a crisis is over may be due to the fact that humans have acute elevations in stress hormones, thus elevating the body's immune response.
The Romans had three words for kissing: basium was the kiss exchanged by acquaintances; osculum, the kiss between close friends; and suavium, the kiss between lovers.
Studies show that one out of every 3,000 children has some form of autistic disorder.
The rush of air produced by a cough moves at a speed approaching 600 miles per hour.
Sweat itself is odorless, only when combined with bacteria that are breaking down dead skin cells does it become smelly. Smelly sweat is called bromohidrosis. Sweat is composed of water, sodium chloride, potassium salts, urea, and lactic acid.
The sensitivity of the human eye is so keen that on a clear, moonless night, a person standing on a mountain can see a match being struck as far as 50 miles away. Much to their amazement, astronauts in orbit were able to see the wakes of ships.
Swimming a quarter of a mile is roughly equal to running one mile.
Grey (or white) is merely the base "colour" of hair. Pigment cells located at the base of each hair follicle produce the natural dominant colour of our youth. However, as a person grows older and reaches middle age, more and more of these pigment cells die and colour is lost from individual hairs. The result is that a person's hair gradually begins to show more and more grey.
There is enough Iron in a human to make a small nail
The Lump of Flesh just forward of your ear canal next to your temple, is called a tragus
A Shank is the part of the sole between the heel and the ball of the foot.
The Talus is the second largest bone in the foot
The two most common surgeries are Biopsies and Cesarean sections
Approximately l3% to 15% of the U.S. population has one or more phobias in a given year (this includes social and specific phobias and agoraphobia).
Specific phobias occur in people of all ages. The average age of onset for social phobia is between 15 and 20 years of age, although it can often begin in childhood.
Although the brain accounts for only 2% of the whole body's mass, it uses 20% of all the oxygen we breathe. A continuous supply of oxygen is necessary for survival. A loss of oxygen for 10 minutes can result in significant neural damage.
Parts of the brain of a severely abused and neglected child can be substantially smaller than that of a healthy child.
It is estimated that a baby loses about half their neurons before they are born. This process is sometimes referred to as pruning and may eliminate neurons that do not receive sufficient input from other neurons.
A study showed that when mothers frequently spoke to their infants, their children learned about 300 more words by age two than did children whose mothers rarely spoke to them.

Birdsong and human speech have similar characteristics. Birds, like humans, learn their complex vocalizations early in life and imitate their adult counterparts to acquire these skills. These two species have evolved a complex hierarchy of specialized forebrain areas where motor and auditory areas interact continuously in order to produce detailed vocalizations.
The optic nerve exits the retina as a single bundle. The exit point within the retina has no receptor cells. This location forms a blind spot in each eye. We rarely notice these spots because they do not overlap within the image formed by the two eyes. Your ophthalmologist can only detect your blind spots by having you close the eye not being tested.
The effects of a stroke depend on the affected blood vessel and the area of brain that it supplies with nutrients. For instance, if the middle cerebral artery is occluded, motor areas in the frontal cortex can be damaged resulting in the loss of voluntary muscle movements on the contralateral, or opposite, side of the body from the damaged side of the brain. This condition is known as hemiplegia.
Strokes or "brain attacks" are the 3rd leading cause of death in the United States. A stroke occurs when the blood flow to the brain is disrupted. Disruption takes place either when a brain artery is blocked or when an artery explodes. Recently, exciting medical breakthroughs have been announced with respect to treating stroke.
Electroencephalogram, or EEG, is a non-invasive technique used to record small changes of electrical activity in the brain with surface electrodes on the scalp. Scientists who study sleep find EEG especially useful. The tiny fluctuations detected with EEG are clear indicators of whether a person is asleep, aroused, or somewhere in between.
Approximately 20% of the blood flowing from the heart is pumped to the brain. The brain needs constant blood flow in order to keep up with the heavy metabolic demands of the neurons. Brain imaging techniques such as functional magnetic resonance imaging (fMRI) rely on this relationship between neural activity and blood flow to produce images of deduced brain activity.
Although the brain accounts for only 2% of the whole body's mass, it uses 20% of all the oxygen we breathe. A continuous supply of oxygen is necessary for survival. A loss of oxygen for 10 minutes can result in significant neural damage.
Measures of brain activity show that during the second half of a child's first year, the prefrontal cortex, the seat of forethought and logic, forms synapses at such a rate that it consumes twice as much energy as an adult brain. That furious pace continues for the child's first decade of life.
The pufferfish, parts of which are eaten as a delicacy in Japan, contains a potent neurotoxin called tetrodotoxin. This toxin blocks sodium channels necessary for the conduction of neural activity. Tetrodotoxin can cause death in approximately 60% of the people who ingest it.
Commisurotomy, the transection of the corpus callosum, is one possible treatment for patients with severe epilepsy. This procedure causes a complete split between the two hemispheres of the brain. As a result of this split, words presented to the patient's far left visual field cannot be read (alexia), and hidden objects placed into the left hand cannot be named (anomia). This is significant evidence for hemispheric specialization.
During the first month of life, the number of connections or synapses, dramatically increases from 50 trillion to 1 quadrillion. If an infant's body grew at a comparable rate, his weight would increase from 8.5 pounds at birth to 170 pounds at one month old.
Did you know that healthy ears actually emit sounds? These sounds are usually very soft, but can occasionally be heard by others. Surprisingly, the sounds are rarely heard by the person whose ear is emitting the sounds! The cause of these sounds is still under debate, but is thought by some to be due to input from the central nervous system.
Nearsightedness (myopia) is the most common visual problem we experience. It is the result of an overly elongated eye, which has become specialized for seeing near objects extremely well.
Yawning is an age-old activity that occurs in reptiles, birds and, of course, mammals. This behavior is controlled by chemicals in the brain called neurotransmitters. Neurotransmitters, such as nitric oxide and dopamine, act in the hypothalamus to induce and control yawning.
The light-detecting receptor cells within the retina, called rods and cones, are actually at the back of the retina under several layers of cells. The neurons and support cells within the retina are fairly translucent, so light is able to pass through them and reach the receptors.
Because receptors (rods and cones) are at the back of the retina, an image actually passes through the retina three times: as light to the receptor cells (back); as neural signals through the initial visual processing of the retina (forward); as neural signals via the optic nerve to the brain (back again).
The human cerebellum, or "little brain", weighs about 150 grams. Located at the lower back of the brain, the cerebellum is key to maintaining posture, walking, and performing coordinated movements. It is also thought to play a role in olfaction or smell.
Nearsighted people can often read the lettering on distant signs by looking through a small hole with one eye. The hole focuses the light entering the eye and replaces the function of the eye's own lens.
Olfactory receptor cells, the neurons in our nose that allow us to smell, are neurons that can regenerate throughout life. Although these cells are continually being born and dying, they maintain the same connections as their ancestors. The result is that once we learn a smell, it always smells the same to us -- despite the fact that there are always new neurons smelling it!
Children as young as four days old can distinguish the vowel sounds of the language in their natural environment from those of a foreign language.
It has been estimated that about one million people in the United States have acquired aphasia. Aphasia is an impairment of the ability to use or comprehend words, usually acquired as a result of a stroke or other brain injury. There are several different types of aphasia depending on the location of the brain injury. There is currently no drug treatment for aphasia although surgery and speech therapy are sometimes successfully used as treatment.
At night, our peripheral vision is better than our foveal (straight on) vision. Hikers at night do better when they look slightly above the trail, and airplane pilots are taught to look for traffic out of the sides of their eyes. This is because our rod cells, photoreceptors that respond best to dim light, are located mostly in the periphery of the retina.
The pupillary light reflex results when light is shined into either eye causing both pupils to constrict. Doctors use this reflex to determine if the reflex pathway through the midbrain has in any way been disrupted. If the reflex fails to produce a response in one or both eyes, the doctor can deduce the location of the malfunction based on which of the eyes failed to respond and which eye was stimulated.
Reading aloud to children helps stimulate brain development, yet only 50% of infants and toddlers are routinely read to by their parents.
Research shows brain growth contains its own rhythm. Certain skills come into preeminence for a period of intensive networking. At three months, the visual cortex dominates synapse formation.
0.5% of the general population has epilepsy. But it is estimated that one in 20 people will have at least one seizure during the course of their life. While seizures are characteristic of epilepsy, having a single seizure does not, in itself, constitute epilepsy. The effects of seizures can vary from complete loss of consciousness to mild shakes or loss of balance.
A child's ability to learn can increase or decrease by 25 percent or more, depending on whether he or she grows up in a stimulating environment.
Scratching an itch is a puzzling biological response, because it seems to hinder rather than help a wound's healing. One theory of why we itch suggests that scratching stimulates the release of endorphins, naturally occurring opiates which block pain sensation. Because scratching injures our skin a little more, we release a flood of endorphins to block the pain of the initial injury more effectively.

It's no accident that telephone numbers in the United States are seven digits long. Our working memory, a very short-term form of memory which stores ideas just long enough for us to understand them, can hold on average a maximum of seven digits. This allows you to look up a phone number and remember it just long enough to dial.
Up to the age of six or seven months, a child can breathe and swallow at the same time. An adult cannot do this.
The human being is the longest-lived of all existing mammals.
One square inch of skin on the human hand contains some 72 feet of nerve fiber
Varicose veins are stretched, dilated veins whose valves do not work properly. The Arizona Heart Institute & Foundation reports that women are three times more likely to develop them than men, and people whose jobs require them to stand for long amounts of time often develop them.
The human body consists of about 60 trillion cells, and each cell has about 10,000 times as many molecules as the Milky Way has stars.
One-fourth of the 206 bones in the human body are located in the feet.
Visual scientists have estimated that, by the age of 60, our eyes have been exposed to more light energy than would be released by a nuclear blast.
The human brain continues sending out electrical wave signals for up to 37 hours following death.
One-fourth of the people who lose their sense of smell also lose their desire for sexual relations.
Water makes up 60 percent of our body weight. Of the water, 8 percent is in the blood, 25 percent in the spaces between cells, and 67 percent inside the cells.
The human brain is insensitive to pain. The suffering of a headache comes not from the organ itself but from the nerve and muscles lining it.
Only about 10 percent of the air in the lungs is actually changed with each cycle of inhaling and exhaling when an at-rest person is breathing, but up to 80 percent can be exchanged during deep breathing or strenuous exercise.
The human eyes can perceive more than 1 million simultaneous visual impressions and are able to discriminate among nearly 8 million gradations of color.
Our hands are recognized by medical professionals as a major source for spreading flu and cold germs. Flu and cold germs can be spread on computer mice and keyboards, chewed pencils, telephones, pens, salad-bar tongs, light switches, door knobs, taxi door handles, and countless other common objects. People can't avoid touching things. To minimize infection, concentrate on keeping hands away from the mouth, nose, and eyes unless the hands are first washed with antibacterial soap, says the Soap and Detergent Association of New York.
Our nails grow at 0.1 mm per day. It takes about three months to replace one entire fingernail.
Identical twins do not have identical fingerprints. No two sets of prints are alike, including those of identical twins.
If a person is "aerophobic," they have an irrational fear of drafts.
If all of the water were drained from the body of an average 160-pound man, the body would weigh 64 pounds.
If all the blood vessels in a single human body were stretched end to end, they would form a string capable of going around the world.
If laid out in a straight line, the average adult's circulatory system would be nearly 60,000 miles long - enough to circle the Earth 2 and a half times.
Human nails and hair do not grow after death. They are simply the last part of the body to disintegrate.
Human reproduction follows lunar time rather than sidereal, or solar, time: Gestation is about 266 days — nine lunar months — and the menstrual period is one lunar month.
Human skin has about 100,000 bacteria per square centimeter. Ten percent of human dry weight is attributed to bacteria.
Humans have about 80,000 genes in their DNA.
Humans have between 100 trillion to 1 quadrillion living cells in their bodies.
Humans, if they are very sensitive, can detect sweetness in a solution of 1 part sugar to 200 parts water. Some moths and butterflies can detect sweetness when the ratio is 1 to 300,000.
Two out of three adults in the United Sates wear glasses at some time.
The easiest sound for the human ear to hear, and those which carry best when pronounced, are, in order, "ah," "aw," "eh," and "oo."
Type O is the most common blood type in the world. Type AB is the rarest. There is also a subtype called A-H, but to date, only three people in the world are known to have it.
The epidermis, the outermost layer of the skin, sheds itself at a rate of about a million cells every 40 minutes.
Of 103.4 million American men, 22.5 million wear a mustache.
Uncontrollable winking is the physical symptom of those suffering from blepharospasms.
The fingernails grow faster on the hand you favor. If you are right-handed; your right fingernails will grow faster; likewise the fingernails on the left hand of a left-handed person. The middle fingernail grows faster than all other nails.

Of the 206 bones in the average adult human body, 106 are found in the hands and feet (54 are in the hands; 52 are in the feet).
Until about age 12, boys cry about as often as girls.
The hair of an adult man or woman can stretch 25 percent of its length without breaking. If it is less elastic, it is not healthy.
On the average, women dream more than men and children dream more than adults. Overall, more people dream in black-and-white than in color.
Until the 1920s, babies in Finland were often delivered in saunas. The heat was thought to help combat infection, and the warm atmosphere was considered pleasing to the infant. The Finns also considered sauna as a holy place.
The heart beats faster during a brisk walk or heated argument than during sexual intercourse.
One individual organ transplant donor can provide organs, bone, and tissue for 50 or more people in need.
Most people's legs are slightly different lengths.
Tooth enamel is the hardest substance manufactured by the human body.
The brain reaches its maximum weight at age 20 - about 3 pounds. Over the next 60 years, as billions of nerve cells die within the brain, it loses about 3 ounces. The brain begins to lose cells at a rate of 50,000 per day by the age of 30.
Most teen-age boys think about sex once every 5 minutes.
Tuberculosis is one of the world's oldest diseases. Some ancient mummies found in Egypt and Peru had tuberculosis.
The BRAT diet is a diet of bananas, rice, applesauce, and toast. The diet is often prescribed for infants with diarrhea.
Nationwide, there are about 15,000 people in comas.
Turkana tribesmen, who live on the barren soils of the Great Rift Valley in Kenya, add iron to their diet by drinking cow's blood - they puncture the cow's jugular vein with a sharp arrow and catch the spurting liquid in a clay jug. The cows, though bled frequently, suffer no ill effect.
The country of Yemen has the world's highest fertility rate among women at 7.6, the world's lowest — Switzerland at 1.5.
Neanderthal man, the first human being in the true sense, had a brain capacity 100 cc larger than modern man's.
Twins are born less frequently born in the eastern part of the world than in the western.
The daughters of a mother who is colorblind and a father who has normal vision will have normal vision. The sons will be colorblind, however.
Nerve signals may travel through nerve or muscle fibers at speeds as high as 200 miles per hour.
The defect of color vision characterized by the inability to see the color red is called protanopia.
Newborn babies are not blind. Studies have shown that newborns have approximately 20/50 vision and can easily discriminate between degrees of brightness.
No one truly has double joints. Contortionists are actually able to stretch the fibrous tissues known as ligaments. Ligaments hold organs in place and fasten bones together. Ligaments normally restrict the movements of certain joints, but some folks find that their ligaments are more flexible than others.
From birth to adolescence, selected bones in the human body fuse together. The last bone to fuse is the collarbone, and this occurs between the ages of 18 and 25.
Hair grows slowest at night. It speeds up in the morning, slows in the afternoon, and grows faster again in the evening. Hair grows faster in summer than in winter.

Hanging in folds when empty, the stomach can stretch to accommodate more than a quart of food.
Harvard researchers have found that people who lose a friend, relative, or loved one through death face great physical risks. They are 14 times more likely than normal to suffer a heart attack the day after the death; two days after the traumatic event, they are at risk five times more than normal.
English ships carried limes to protect the sailors from scurvy. American ships carried cranberries.
Even if 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 are removed, the human body can still survive.
Every person has nearly 400,000 radioactive atoms disintegrating into other atoms in his or her body each second. But there's no need to worry about falling apart. Each body cell contains an average of 90 trillion atoms — 225 million times that 400,000.
Experts at the Center of Ergonomics at the University of Michigan have concluded that the tilt created where the seat and back of a rocking chair come together should be greater than 90 degrees — 120 degrees are good, or even 135 — for the health of the lower back.
False teeth are often radioactive. Approximately 1 million Americans wear some form of denture; half of these dentures are made of a porcelain compound laced with minute amounts of uranium to stimulate fluorescence. Without the uranium additive, the dentures would be a dull green color when seen under artificial light.
Following a family move, a series of studies have discovered that boys between the ages of 6 and 11 tend to have problems adjusting to new environments, particularly school. The research showed that moving during those ages could be so traumatic for boys as to cause a drop in academic achievement or even I.Q. The results were not conclusive for girls.
There are eight bones in a human wrist.
There are more than 10 trillion living cells in the human body.
The body has 70,000 miles of blood vessels. The heart pumps blood through this labyrinth and back again once every minute.
There are more than 100 different viruses that cause the common cold.
The body’s daily requirement of vitamins and minerals is less than a thimbleful.
Moderate dancing burns 250 to 300 calories an hour. Twenty minutes of moderate dancing will elevate heart rate up to aerobic levels. One study found polkas, swing dancing, and waltzes to be particularly effective for weight loss.
There are ten human body parts that are only three letters long: eye, hip, arm, leg, ear, toe, jaw, rib, lip, gum.
The body's largest internal organ is the small intestine at an average length of 15 to 20 feet and has a diameter of no more than an inch and a half. The large intestine measures an average of 5 feet.
More than half of school-age children in the U.S. have no cavities in their permanent teeth, compared with only 26 percent who were cavity-free in the early ‘70s, the American Dental Association has reported.
Today, American dentists use some 13 tons of gold each year for crowns, bridges, inlays and dentures. The reason? Gold is non-toxic, it can be shaped easily, and it is tough -- it never wears, corrodes or tarnishes.
The brain is surrounded by a membrane containing veins and arteries. This membrane is filled with nerves of feeling. However, the brain itself has no feeling; if it is cut into, the person feels no pain.
Most people by the age of sixty have lost 50 percent of their taste buds and 40 percent of their ability to smell.
Tongue prints are as unique as fingerprints.
The brain of Neanderthal man was larger than that of modern man.
Medical experts have observed that people who stutter rarely do when they are alone or talking to a pet.
The average person takes from twelve to eighteen breaths per minute.
Medical experts warn that compulsive exercising can be just as bad for a person as no exercise at all. The human body needs 24 hours without exercise about once a week in order to cleanse itself of lactic acid and other waste products of strenuous activity.
The average person's field of vision encompasses a 200-degree wide angle.
Men have more blood than women. Men have 1.5 gallons as compared to 0.875 gallons for women.
The average person's hand flexes its finger joints 25 million times during a lifetime.
Men over the age of 24 shave an average of six times a week.
The average person's total skin covering would weigh about 6 pounds if collected in one mass.
Men reach the peak of their sexual powers in their late teens or early twenties, and then begin to slowly decline. Women, however, do not reach their sexual peak until their late twenties or early thirties, and then remain at this level through their late fifties or early sixties.
The average square inch of skin holds 650 sweat glands, 20 blood vessels, 60,000 melanocytes (pigment cells), and more than a thousand nerve endings.
Men who eat 10 or more weekly servings of tomato-based foods cut their prostate cancer risk by 45 percent in a Harvard study of 47,000 middle-age male health professionals. Tomatoes are rich in lycopene, an antioxidant. Juice, salad, soup, even pizza, helped
The average woman consumes 2,000 calories a day, the average man about 2,500; but if you had the metabolism of a shrew you would need to consume about 200,000 calories a day. Metabolic rate is the sum of all the chemical reactions occurring in the body at one time. The faster the reactions, the higher your metabolism and the more calories you need to consume. Smaller animals tend to have higher metabolic rates because they have to work harder to keep their bodies warm.
Men who take steroids to build muscle are believed to have extremely low sperm counts. So reported a British Centre of Reproductive Medicine study, which revealed that it takes one to three years after giving up steroids for a man to recover enough to father a child.
The average women's thighs are one and a half times larger in circumference than the average man's.
Men with mustaches may be allergic to their own lip hair. That is because mustaches may harbor airborne pollens that trigger allergies.
Midgets and dwarfs almost always have normal-sized children, even if both parents are midgets or dwarfs.
Each red blood cell lives an average of 4 months and travels between the lungs and other tissues 75,000 times before returning to the bone marrow to die.

Each square inch of human skin consists of 19 million cells, 60 hairs, 90 oil glands, 19 feet of blood vessels, 625 sweat glands, and 19,000 sensory cells.
Eighty percent of the average human brain is water.
Electrical nerve stimulation may help reduce chronic pain in cancer patients, especially those whose cancer has spread to the bones, say researchers at the University of Texas Southwestern Medical School in Dallas. Some cancers that spread to bones produce severe chronic pain that is unresponsive to analgesic drugs, including morphine.
The average human scalp contains between 120,000 and 150,000 hairs.
Licorice can raise your blood pressure.
The average life span of a fifth-century man in England was 30 years.
Man has tiny bones once meant for a tail and unworkable muscles once meant to move his ears.
The average lifespan of a human being's taste bud is 7-10 days.
Man's three-pound brain is the most complex and orderly arrangement of matter known in the universe.
Many children occasionally walk in their sleep. Sleepwalking is ordinarily a phase in the growing-up process. Because parts of the child's brain are immature, dreams can be stimulating enough to cause a youngster to take a nocturnal stroll. About 25 percent of all children have one or more sleepwalking episodes between the ages of 7 and 12, according to sleep researchers.
Because alcohol causes cells to become dehydrated, one way to minimize a hangover is to drink a couple of glasses of water after each alcoholic drink, thus preventing dehydration. The most common symptom of a hangover is the same as that of mild dehydration — a headache.

Because of their extreme elasticity, the lungs are 100 times easier to blow up than a child’s toy balloon.
Between ages 30 and 70, a nose may lengthen and widen by as much as half an inch and the ears may be a quarter-inch longer - due to the fact that cartilage is one of the few tissues that continue to grow as we age.
Blype is the skin that peels off after bad sunburn.
Brain-wave activity in humans changes when we catch the punch line of a joke.
Children born in the month of May are on the average 200 grams heavier at birth than children born in any other month.
Drinking lowers rather than raises the body temperature. There is an illusion of heat because alcohol causes the capillaries to dilate and fill with blood. In very cold weather, drinking alcoholic beverages can lead to frostbite.
During menstruation, the sensitivity of a woman's middle finger is reduced.
During pregnancy, the uterus expands to 500 times its normal size.
The average male adult can bench-press 88 percent of his body weight, having 70 to 80 pounds of muscle.
The average person can live up to eleven days without water, assuming a mean temperature of 60 degrees Fahrenheit.
Medical experts are perturbed that TV medical dramas suggest that people who receive CPR usually recover; the truth is, only about 15 percent of victims survive after receiving CPR.
The average person takes 8,000 to 10,000 steps a day, according to the American Podiatric Association.
As much as six percent of the world's population may experience sleep paralysis, the inability to move and speak for several minutes after awakening.
At least 100,000 different chemical reactions occur in the normal human brain every second.
At sea level, there are 2,000 pounds of air pressure on each square foot of your body.
At Tokyo's Keio University Hospital, 30 percent of the outpatients diagnosed with throat polyps atttributed the cause of the affliction to singing karaoke.
Babies are born with 300 bones, but by adulthood, we have only 206 in our bodies.
Based on research with the human body's internal clock, the period between the hours of 4 and 6 in the afternoon is when people are the most irritable. Evidence has shown that more human bites are treated in hospitals at this time of the day than any other.
Beards are the fastest growing hairs on the human body. If the average man never trimmed his beard, it would grow to nearly 30 feet long in his lifetime.
The average brain comprises 2 percent of a person's total body weight. Yet it requires 25 percent of all oxygen used by the body, as opposed to 12 percent used by the kidneys and 7 percent by the heart.
The average digestive tract of an adult is 30 feet in length.
It requires the use of 72 muscles to speak a single word.
The average female between the ages of 20 and 44 is more likely to be overweight than are males in the same age category.
It takes 17 facial muscles to smile but 42 to frown.
The average human eye can distinguish about 500 different shades of gray.
It takes the human eyes an hour to adapt completely to seeing in the dark. Once adapted, however, the eyes are about 100,000 times more sensitive to light than they are in bright sunlight.
The average human eyelash lives about 150 days.
Lack of sleep is becoming such a problem for American adults that 8 percent say they occasionally or frequently fall asleep at work, and 19 percent say they make errors because of sleepiness.
The average human has about 10,000 taste buds — however; they're not all on the tongue. Some are under the tongue; some are on the inside of the cheeks; some are on the roof of the mouth. Some can even be found on the lips — these are especially sensitive to salt.
Laughing is aerobic. It provides a workout for the diaphragm and increases the body's ability to use oxygen.

The average human heart beats about 100,000 times every 24 hours. In a 72-year lifetime, the heart beats more than 2.5 billion times.
Laughing lowers levels of stress hormones and strengthens the immune system. Six-year-olds laugh an average of 300 times a day. Adults only laugh 15 to 100 times a day.
Among his many achievements, the astronomer Johannes Kepler chalked up one about man's inner world. It was Kepler who realized that man's visual apparatus is so constructed that it can produce only inverted images.
An adult human head weighs about 12 pounds (5.4kg), or the same as a light bowling ball.
An adult sitting in a relaxed position inhales approximately one pint of air with every breath.
An average man on an average day excretes two and a half quarts of sweat.
An unusual eating disorder called tomatophagia — but also known as pica — is blamed on iron deficiency anemia. People with tomatophagia develop unusual cravings for such things as tomatoes, ice, detergent, starch, clay, or even dirt.

Ancient Egyptians regarded the heart as the center of intelligence and emotion. They believed the brain to have no signifigance whatsoever, and in the important process of mummification, the brain was removed through the nose and discarded.
Another word for the human thumb is "pollex."
In the latter part of the 18th century, Prussian surgeons treated stutterers by snipping off portions of their tongues.
In the past few years, doctors have identified more than 100 sleep disorders, but the one most people suffer from is simply not taking the time to get enough sleep.
In the second it takes to turn the page of a book, you will lose about 3 million red blood cells. During that same second, your bone marrow will have produced the same number of new ones.
Iridescent beetle shells were the source of the earliest eye glitter ever used — devised by the ancient Egyptians.
It has been determined that one brow wrinkle is the result of 200,000 frowns.
It has been medically proven that pessimism raises blood pressure. The more pessimistic a person is, the more likely he or she is to die earlier than optimistic counterparts.

It is a common myth that chocolate aggravates acne. Experiments conducted at the University of Pennsylvania and the U.S. Naval Academy found that consumption of chocolate – even frequent daily dietary intake – had no effect on the incidence of acne. Professional dermatologists no longer link acne with diet.
It is a comparatively recent insight that light travels from the object to the eye. Until about 400 years ago, it was thought that there was "something" in the eye that went out and saw the object.

It is estimated that a healthy individual releases 3.5 oz. of gas in a single flatulent emission, or about 17 oz. in a day.
It is impossible to drink too much water on a hike. Hikers' biggest problem is dehydration, which leads to fatigue. This increases the possibility of injuring oneself. Hikers should avoid beverages with caffeine and alcohol, both of which can dehydrate.
Anthropologists use a standard height of 4 feet 11 inches to determine if a group of people are pygmies. The average adult male must be less than 59 inches in height.
Approximately five million Americans suffer from a recurring ailment known as SAD. This is an acronym for "seasonal affective disorder." This wintertime syndrome can be treated with light.
As long as 4,500 years ago, the Egyptians used gold in dentistry. Remarkable examples of the artistry of these early orthodontists have been found, perfectly preserved, by archaeologists of our own time
According to a survey, women prefer blue bedrooms more than other colors; men are happier with white bedrooms.
According to acupuncturists, there is a point on the head that you can press to control your appetite. It is located in the hollow just in front of the flap of the ear.
According to Aristotle, the liver served as the body's seat of emotions.
According to Aristotle, wind direction determined whether a baby would be a boy or a girl.
According to research conducted by Soviet scientists, girls born to men who are older than 50 have an average life span that is six years shorter than their brothers. They believe the X, or female, chromosome a father passes to his daughter contains the gene that determines longevity.
According to researchers at the University of Texas, babies like pretty faces better than plain ones.
According to the Anxiety Disorders Association, one in 11 people suffer from some kind of phobia at some time in their lives. Psychologists know little about the origin of phobias. Women are more prone to phobias than men.
If the skin of a 150-pound person were spread out flat, it would cover approximately 20 square feet.
If you are afraid that you might die laughing — you are suffering from cherophobia.
If you are mysophobic, you have an intense fear of infection.
If you are right-handed, you will tend to chew your food on the right side of the mouth. If you are left-handed, you will tend to chew your food on the left.
If you never get thirsty, you need to drink more water. When the human body is dehydrated, its thirst mechanism shuts off.
In all of history, the most destructive disease is malaria. More than 1.5 million people die from malaria every year.
In ancient Rome, gold salves were used for the treatment of skin ulcers. Today, gold leaf plays an important role in the treatment of chronic ulcers.
In medieval Europe, alchemists mixed powdered gold into drinks to "comfort sore limbs," one of the earliest references to arthritis.
In one year, the average human heart circulates from 770,000 to 1.6 million gallons of blood through the body. This is enough fluid to fill 200 tank cars, each with a capacity of 8,000 gallons.
In the adult human body, there are 46 miles of nerves.
According to the Centers for Disease Control and Prevention (CDC), 18 million courses of antibiotics are prescribed for the common cold in the United States per year. Research shows that colds are caused by viruses. Fifty million unnecessary antibiotics are prescribed for viral respiratory infections.
Although only about 6 percent of women fail to cry at least once a month, 50 percent of men fail to cry that often.
Among a sampling of American seventh-graders who were given the SAT test, 55 percent of the children who did “exceptionally well” on either the math or verbal sections were nearsighted.
A human can see a candle flame from 50 kilometers on a clear, dark night.
A human can taste one gram of salt in 500 liters of water (0.0001M).
A loss of 20 percent of the body's water would result in certain and painful death. Ordinarily the body cannot go more than a week and a half without water; the longest recorded time anyone has gone without water is eleven days.
A newborn baby's head accounts for about one-quarter of its entire weight.
A newly formed nerve cell is called a neuroblast.
A normal person has two true vocal chords. We also have two false vocal chords, which have no direct role in producing sound.
A person breathes almost 7 quarts of air every minute.
A person who is "scoptophobic" has an intense fear of being seen.
A person's nose and ears continue to grow throughout his or her life.
A recent study found that 75 percent of headache patients felt relief when they rubbed capsaicin (the component that makes chile peppers hot) on their nose.
A recent U.S. study purports that there are fewer births 9 months after a heat wave. The study found that an increase of 12 degrees Celsius (approximately 21.6 degrees Fahrenheit) in summer temperatures reduces births the following spring by up to 6 percent. Researchers at Kinsey Institute for Sex Research at Indiana University concluded that high temperatures could reduce people's sense of well-being, which could result in a reduction in sexual interest. Another study found lower sperm counts and higher rates of miscarriage during hot weather.
A simple, moderately severe sunburn damages the blood vessels to such an extent that it takes four to fifteen months for them to return to their normal condition.
A sneeze can travel as fast as 100 miles per hour. It is impossible to sneeze and keep ones eye's open at the same time.
A survey conducted at Iowa State College in 1969 suggests that a parent's stress at the time on conception plays a major role in determining a baby's sex. The child tends to be of the same sex as the parent who is under less stress.
A Swiss study found that a majority of women unconsciously choose mates with a body odor that differs from their own natural scents, which, as a result, ensures better immune protection for their children. "Longevity" magazine reported that the genes that battle disease-provoking substances also influence body odor.

A United Parcel Service delivery person typically makes up to 300 pickups or deliveries a day. That compares to someone doing 600 sets of step aerobics a day.
A woman's arthritic pains will almost always disappear as soon as she becomes pregnant.
A woman's heart beats faster than a man's.
About 75 percent of Americans will have foot problems of one sort or another at some time in their lives.
According to a 1999 survey conducted by the National Sleep Foundation, of those people who snore, 19 percent snore so loudly that they can be heard through a closed door.
A “nullipara” is a woman who has never borne a child.
A 3-week old embryo is no larger than a sesame seed. A 1-month old fetus’s body is no heavier than an envelope and a sheet of paper. Its hand is no bigger than a teardrop.
A bird's eye takes up about 50 percent of its head; our eyes take up about 5 percent of our head. To be comparable to a bird's eyes, our eyes would have to be the size of baseballs.
A bowl of lime Jell-O, when hooked up to an EEG machine, exhibited movement which is virtually identical to the brain waves of a healthy adult man or woman.
A fetus in the womb can hear. Tests have shown that fetuses respond to various sounds just as vigorously as they respond to pressures and internal sensations.
A four-month-old fetus will startle and turn away if a bright light is flashed on its mother's belly. Babies in the womb will also react to sudden loud noises, even if their mother's ears are muffled.
A healthy man who is good physical shape has about 12 to 15 percent body fat. A woman in good shape has between 15 to 18 percent. The models used in most of the advertising for abdominal machines, on the other hand, have less than 10 percent body fat.
The thumbnail grows the slowest; the middle nail grows the fastest.
The white part of your fingernail is called the lunula.
The word salmonella, referring to bacteria that enter a person's digestive tract in contaminated food and causing food poisoning, has nothing to do with fish. It was named after U.S. pathologist Daniel E. Salmon.
The world's first test-tube twins were born in June 1981.
There are 110 calories per hour consumed during an hour of typing — only 30 more than those used while sleeping..
There are 3 million stutterers in the United States and a similar proportion in every other part of the world.
There are 35 million digestive glands in the stomach.
There are 62,000 miles of arteries, capillaries, and veins in the adult human body.
There are about 2 million sweat glands in the average human body. The average adult loses 540 calories with every liter of sweat. Men sweat about 40% more than women.
There are approximately 250,000 sweat glands in your feet and they sweat as much as 8 ounces of moisture per day.
A human can detect one drop of perfume diffused throughout a three-room apartment.
A human can detect the wing of a bee falling on your cheek from a height of one centimeter.
A human can hear the tick of a watch from 6 meters in very quiet conditions
The short-term memory capacity for most people is between five and nine items or digits. This is one reason that phone numbers were kept to seven digits (not including area code).
Synesthesia is a rare condition in which the senses are combined. Synesthetes see words, taste colors and shapes, and feel flavors.
The simple act of walking requires the use of 200 muscles in the human body. 40 or so will lift your leg and move it forward.
The African bushman lives in a quiet, remote environment and has no measurable hearing loss at age 60.

The size of your foot is approximately the size of your forearm.
The average adult has between 40 and 50 billion fat cells.
The average adult stands 0.4 inch (1 cm) taller in the morning than in the evening, because the cartilage in the spine compresses during the day.
The skeleton of an average 160 pound body weighs about 29 pounds.
The skin is only about as deep as the tip of a ball-point pen. First-degree burns affect only the very top layers of the skin; second-degree burns, midway through the skin's thickness. Third-degree burns penetrate and damage the entire thickness of the skin.
The skin of the armpits can harbor up to 516,000 bacteria per square inch, while drier areas, such as the forearm, have only about 13,000 bacteria per square inch.
The soft mass of the adult brain is motionless. Though it consumes up to 25 percent of the blood's oxygen supply, it does not grow, divide, or contract.
The sound of a snore (up to 69 decibels) can be almost as loud as the noise of a pneumatic drill (70–90 decibels).
The strongest bone in the body, the thigh bone, is hollow. Ounce for ounce, it has a greater pressure tolerance and bearing strength than a rod of equivalent size in cast steel.
The strongest muscle in the body is the tongue.
The substance that human blood resembles most closely in terms of chemical composition in sea water.
The swine flu vaccine in 1976 caused more death and illness than the disease it was intended to prevent.
The thumb is such a major player in the human body that it has a special section, separate from the area that controls the fingers, reserved for it in the brain.
"Mageiricophobia" is the intense fear of having to cook.
“Villi”, finger-like projections on the small intestine (their purpose is to increase the surface area for water and nutrient absorption) are four-hundredths of an inch long.
25 trillion cells travel through the bloodstream – a stack of 500 would only measure 0.04 inches high.