One human hair can support 3 ounces.
191
It takes twice as long to lose new muscle if you stop working out than it did to gain it.
127
The adult human brain weighs about 3 pounds (1,300-1,400 g).
99
Enamel is hardest substance in the human body.
61
It takes about 20 seconds for a red blood cell to circle the whole body.
102
The average sperm cell swims at 8 inches per hour.
76
Yawns are more contagious among people with closer relationships.
163
The human brain uses approximately as much energy as a 10 watt light bulb.
120