Fingernails grow nearly 4 times faster than toenails.
31
The brain can stay alive for 4 to 6 minutes without oxygen. After that cells begin die.
193
Only 1% of bacteria cause disease.
45
The human heart creates enough pressure to squirt blood 30 ft.
37
The aorta, the largest artery in the body, is almost the diameter of a garden hose.
37
If you unfolded your brain, it would cover an ironing board.
42
Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18