10 Things You Didn't Know About Your Body

1. YOUR BODY IS A WALKING CHEMISTRY LAB. It contains over 40 elements, 99% of them carbon, hydrogen, nitrogen, and oxy-gen. (Hydrogen and oxygen alone are 87% of your body mass— body cells are mostly water—mixed hydrogen and oxygen.)

2. OXYGEN CAN KILL YOU. We need it to live. In fact, adult humans need to inhale about 88 pounds of oxygen every day. But concentrated doses for extended periods destroy lung cells, leading to coma and death. Same with water. It’s the basis of life, but too much too soon dilutes the bloodstream and impairs electrolyte balance, possibly leading to cardiac arrest. So breathe and drink responsibly.
Oddities worth noting:
•Women feel more pain than men.
•Human brains continue to generate electrical impulses for more than a day after death.
•Human bones have the same tensile strength as steel but are roughly 50 times lighter.
•You are born with adult-size eyes, but your ears and nose keep growing throughout your life.

3. YOUR LIVER IS YOUR LARGEST INTERNAL ORGAN. (Skin is the largest organ overall.) An adult male liver is—espe-cially on Monday nights—about the size of a football. It weighs 3 pounds and lurks in your upper right abdomen, protected by ribs. Other than the brain, it’s your most com-plex, versatile organ. Think of it as the body’s chemical processing plant.
Liver function affects almost every bodily process. It filters toxins (purifying a liter of blood every minute), regulates fat digestion, aids hormonal balance. It’s also an efficient packager of nutrients, storing and distributing what you need for growth and maintenance. One exam-ple: it absorbs glucose from digested food, sends what is needed into the bloodstream, then converts and “shelves” the rest as glycogen for future use. When your body needs more fuel to burn, your liver reconverts that glycogen into glucose.

4. YOUR HEART IS IN THE RIGHT PLACE. But that isn’t on the left side of your chest. It’s near the center, between the lungs. It angles slightly left, which is where you notice its beating. In most adults, the heart is about twice the size of a fist.
A normal heart beats about 100,000 times a day—35 million times a year. Assuming an average life span, your heart will beat between 2.5 and 3.0 billion times, pumping some 55,000,000 gallons of blood! An industrious little mus-cle indeed. About 6 quarts of blood circulate through your entire system every 20 seconds. Each 24 hours, that blood travels 12,000 miles. Your heart muscle uses about the same force to pump blood as you’d use to squeeze a tennis ball, which can squirt a stream of blood about 30 feet.
The aorta, the largest artery in the body, is as wide as a gar-den hose. If you were to unravel all the blood vessels, including capillaries, in your body, they’d stretch 62,000 miles, about two and a half times around the Earth. Capillaries are so tiny that 10 of them braided together could fit inside a human hair.
The human heart continues to beat even when removed from the body or cut to pieces.

5. LOCATION, LOCATION, LOCATION. How long your body lasts depends partly on where your body is living. According to a World Bank survey, worldwide average life expectancy has risen to 67. Japan’s expected age is 81; public-health, AIDS-challenged Swaziland a mere 32.6.
A report ranking more than 170 countries according to various factors revealed that the best places to live were over-whelmingly Western societies. For the fourth straight year, Norway topped the list, followed closely by Sweden, Aus-tralia, Canada, the Netherlands, Belgium, Iceland, the U.S., Japan, and Ireland. Most endangered: Niger, Burkina Faso, Mali, and Sierra Leone. Norwegians born between 2000 and 2005 have an estimated life of 78.9 years; Zambians born those same years can expect only 32.4.
Perhaps unsurprisingly, the following “healthiest places” have universal health care progams: Norway, Sweden, Aus-tralia, Canada, the Netherlands, Belgium, Japan, and Ireland. The U.S. and Iceland seem uninterested in that social ser-vice.

6. ANIMAL, VEGETABLE, MINERAL. Your body is made up of about 100 trillion cells, most of which are microbes: fungi, bacteria, viruses, and other alien particles. Your skin alone hosts more living organisms than the total human population of Earth.
Your gut is home to about 2.2 pounds of bacteria—even before the chili down at Paco’s. There are more bacteria than human cells in and on your body. Every square inch contains an average of 32 million bacteria. In fact, about 10% of your dry weight is from bacteria, so consider personal hygiene when dieting. There are more bacteria in your mouth than people in North America.

7. IT AIN’T NECESSARILY SO. Despite the biblical story of Adam trading a rib for a wife, men have the same number of ribs as women. In each case, 24. One of every 20 humans has one pair more or less.

8. YOU’RE PROBABLY NOT MULTITASKING AS WELL AS YOU THINK. Neurological research shows that most people should not try to do too much at once. Distractions impede perfor-mance because of human cognitive limits.
Driving while talking on a cell phone, even with a head-set, reduces awareness levels and cuts response time up to a full second—lethal at 60 mph.
Young brains fire faster. But they’re easily distracted, and they take longer to regain efficiency, according to Oxford University researchers. Test groups of 18 to 21-year-olds and 35 to 39-year-olds were given 90 seconds to code images into numbers. The youngsters were 10% more efficient when not interrupted. But after interruptions to both groups, they per-formed no better than the oldies.

9. LEFT-LEANING? About 17% of us are left-handed—50% more males than females. (True of gorillas and chimps also!) Lefties are better at sports that require keen spatial judgment and fast reaction. But there’s no evidence that they are smarter or more creative than right-handers. Left-handedness is as-sociated both with high achievement and with neurological disorders like Down’s syndrome, dyslexia, and autism.
It starts early. Whichever thumb an embryo sucks usually correlates with the child’s subsequent handedness. Some the-orize a connection between left-handedness and high uterine testosterone levels; others suggest that right-brain emphasis implied by left-handedness may incline babies toward artistic creativity.
People tend to chew their food on the same side as their dominant hand. Southeast Asia and Eastern Europe have the most lefties in the world. It is comparatively uncommon among Europeans and Africans. Right-handers live, on average, nine years longer than left-handed people. (Maybe partly because left-handed people are injured or killed using machinery or implements designed for right-handed people?)

10. YOU’RE ALL WET. According to some water industry esti-mates, the average American uses 3,000 gallons of water a month for all purposes. That means 12,000 for a family of four. Over a typical lifetime, we will each generate about 10,000 gallons of saliva and 12,000 gallons of urine.
We lose water through 2,000,000 sweat glands (250,000 in our feet alone), also via exhaled breath and elimination of waste.

Water is the only substance naturally present in all three states of matter—liquid, solid (ice), and gas (water vapor or steam). It’s present in two of those forms in your body. For your sake we hope there’s neither ice nor steam. Your brain is 75% water, 22% bones, over 80% blood. Less than 3% of all water on Earth is drinkable; 90% of it is in Antarctica—for the moment. Be very worried.