It takes about 20 seconds for a red blood cell to circle the whole body.
102
Pet dogs and elephants are the only animals that seem to instinctively understand human gesture.
14
Yawns are more contagious among people with closer relationships.
163
It takes twice as long to lose new muscle if you stop working out than it did to gain it.
127
Human hair and fingernails continue to grow after death.
7
In ancient Egypt, priests plucked EVERY hair from their bodies, including their eyebrows and eyelashes.
130
By weight, Bone is five times stronger than steel.
417
The human brain is more active during sleep than during the day.
28