16 MYSTERIOUS THINGS ABOUT HUMAN BODY

16: Need for Sleep

If you say that you're dying to get a good night's sleep, you could mean that literally. You can go without eating for weeks without succumbing, but eleven days is tops for going without sleep. After eleven days, you'll be asleep -- forever!

15: Head Weight

No wonder babies have such a hard time holding up their heads: The human head is one-quarter of our total length at birth but only one-eighth of our total length by the time we reach adulthood

If you're cli­pping your fingernails more often than your toenails, that's only natural. The nails that get the most exposure and are used most frequently grow the fastest. Fingernails grow fastest on the hand that you write with and on the longest fingers. On average, nails grow about one-tenth of an inch each month. 

13: Hair Color and Count

Blondes may or may not have more fun, but they definitely have more hair. Hair color helps determine how dense the hair on your head is, and blondes (only natural ones, of course), top the list. The average human head 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. People with black hair tend to have about 110,000 follicles, while those with brown hair are right on target with 100,000 follicles. Redheads have the least dense hair, averaging about 86,000 follicles.

12: Snore Loudness

By 60 years of age, 60-percent of men and 40-percent of women will snore. But the sound of a snore can seem deaf­ening. While snores average around 60 decibels, the noise level of normal speech, they can reach more than 80 decibels. Eighty decibels is as loud as the sound of a pneumatic drill breaking up concrete. Noise levels over 85 decibels are considered hazardous to the human ear.

11: Saliva Quantity

You may not want to swim in your spit, but if you saved it all up, you could. In a lifetime, the average person produces about 25,000 quarts of saliva -- enough to fill two swimming pools!

10: Blood Distance

Blood has a long road to travel: Laid end to end, there are about 60,000 miles of blood vessels in the human body. And the hard-working heart pumps about 2,000 gallons of blood through those vessels every day.

9: Sneeze Speed

The air from a human sneeze can travel at speeds of 100 miles per hour or more -- another good reason to cover your nose and mouth when you sneeze -- or duck when you hear one coming your way.

8: Source of Body Odor

Th­e source of smelly feet, like smelly armpits, is ­sweat. And people sweat buckets from their feet. A pair of feet have 500,000 sweat glands and can produce more than a pint of sweat a day.

7: Bacteria

This will really make your skin crawl: Every square inc­h of skin on the human body has about 32 million bacteria on it, but fortunately, the vast majority of them are harmless.

6: Long Intestines

The small intestine is about four times as long as the average adult is tall. If it weren't looped back and forth upon itself, its length of 18 to 23 feet wouldn't fit into the abdominal cavity, making things rather messy.

5: Scent Remembering

Your nose is not as sensitive as a dog's, but it can remember 50,000 different scents.

4: New Stomach

Did you know that you get a new stomach lining every three to four days? If you didn't, the strong acids your stomach uses to digest food would also digest your stomach.

3: Bone Count

An adult has fewer Bones than a baby. We start off life with 350 bones, but because bones fuse together during growth, we end up with only 206 as adults.

2: Shedding

Your pet isn't the only one in the house with a shedding problem. Humans shed about 600,000 particles of skin every hour. That works out to about 1.5 pounds each year, so the average person will lose around 105 pounds of skin by age 70.

1: Tongue Print

D­on't stick out your tongue if you want to hide your identity. Similar to fingerprints, everyone also has a unique tongue print!