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
It takes twice as long to lose new muscle if you stop working out than it did to gain it.
127
It takes about 20 seconds for a red blood cell to circle the whole body.
102
Enamel is hardest substance in the human body.
61
The largest cell in the human body is the female egg and the smallest is the male sperm.
682
Dogs can be trained to identify the scent of lung cancer long before symptoms develop.
190
Our eyes are always the same size from birth, but our nose and ears never stop growing.
266