Your brain uses 20% of the oxygen that enters your bloodstream, and the average length of most dreams is only 2-3 seconds.

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.

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.

Sneezes regularly exceed 100 mph. Coughs clock in at about 60 mph. The average person, man or woman, blinks about 13 times a minute.

At only 6-13 weeks of fetal 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.

Your nose can remember 50,000 different scents. While a bloodhound's nose may be a million times more sensitive than a human's, 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.

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.

It takes 17 muscles to smile and 43 to frown.

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.

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.