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 doesn't stop developing until about 25 years old.
102
It takes about 20 seconds for a red blood cell to circle the whole body.
102
The human brain is very soft, having a consistency similar to soft gelatin or firm tofu.
13
Your heart will pump about 212 million liters in its lifetime.
26
Women have about four times as many foot problems as men; lifelong patterns of wearing high heels often are the culprit.
111
Poor eyesight (myopia) is associated with higher IQ.
232
It would take about 1,200,000 mosquitoes to fully drain the average human body of blood.
217