16 Unusual Facts About the Human Body, 7-16

This page includes 10 more unusual facts about the human body, including the straight story on sneezes.

7. 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.

8. 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.

9. 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.

10. 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.

11. 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!

12. 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.

13. 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.

14. 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.

15. 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.

16. 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!

CONTRIBUTING WRITERS:

Helen Davies, Marjorie Dorfman, Mary Fons, Deborah Hawkins, Martin Hintz, Linnea Lundgren, David Priess, Julia Clark Robinson, Paul Seaburn, Heidi Stevens, and Steve Theunissen