The adult human brain weighs about 3 pounds (1,300-1,400 g).
99
Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18
After age 30, the brain begins to lose about 50,000 neurons per day - shrinking the brain .25% each year.
55
The largest cell in the human body is the female egg and the smallest is the male sperm.
682
There are times when you're walking that the pressure on your feet exceeds your body weight, and when you're running, it can be three or four times your weight.
62
Your thumb is about the same size as your nose.
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Women have about four times as many foot problems as men; lifelong patterns of wearing high heels often are the culprit.
111
Your body is creating and killing about 2.4 million red blood cells per second.
17