Every year your body replaces 98% of your atoms.
119
The human brain doesn't stop developing until about 25 years old.
102
Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18
It takes about 20 seconds for a red blood cell to circle the whole body.
102
If you are cold you are more likely to be hungry because you use energy to keep warm.
143
The human brain is very soft, having a consistency similar to soft gelatin or firm tofu.
13
The average sperm cell swims at 8 inches per hour.
76