Your thumb is about the same size as your nose.
124
The average sperm cell swims at 8 inches per hour.
76
Enamel is hardest substance in the human body.
61
Women have about four times as many foot problems as men; lifelong patterns of wearing high heels often are the culprit.
111
The average person's skin weighs twice as much as their brain.
131
Every year your body replaces 98% of your atoms.
119
The human brain doesn't stop developing until about 25 years old.
102
It takes twice as long to lose new muscle if you stop working out than it did to gain it.
127