Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18
If your DNA was stretched out it would reach to the moon 6,000 times.
256
The largest cell in the human body is the female egg and the smallest is the male sperm.
682
Enamel is hardest substance in the human body.
61
The human brain is very soft, having a consistency similar to soft gelatin or firm tofu.
13
If you are cold you are more likely to be hungry because you use energy to keep warm.
143
Staying awake for 17 hours is the same for your body as drinking 2 glasses of wine.
193