Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18
We blink 25 times a minute.
51
While 7 men in 100 have some form of color blindness, only 1 woman in 1,000 suffers from it.
50
Unconsciousness will occur after 8-10 seconds after loss of blood supply to the brain.
93
We are born with 350 bones, and die with 206.
135
Redheads require up to 20% more anesthesia to be knocked out.
112
During menstruation, the sensitivity of a woman's middle finger is reduced.
47