It takes about 20 seconds for a red blood cell to circle the whole body.
102
Coughing can cause air to move through your windpipe faster than the speed of sound - over a thousand feet per second!
197
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 uses approximately as much energy as a 10 watt light bulb.
120
If your DNA was stretched out it would reach to the moon 6,000 times.
256
Yawns are more contagious among people with closer relationships.
163
Women have about four times as many foot problems as men; lifelong patterns of wearing high heels often are the culprit.
111
The average sperm cell swims at 8 inches per hour.
76