Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18
The human brain is very soft, having a consistency similar to soft gelatin or firm tofu.
13
After age 30, the brain begins to lose about 50,000 neurons per day - shrinking the brain .25% each year.
55
Oxygen, carbon, hydrogen and nitrogen make up 90% of the human body.
118
If you are cold you are more likely to be hungry because you use energy to keep warm.
143
The largest cell in the human body is the female egg and the smallest is the male sperm.
682
One human hair can support 3 ounces.
191
The average sperm cell swims at 8 inches per hour.
76