Enamel is hardest substance in the human body.
61
An Indian man known as "Snake Manu" can put small snakes, including deadly cobras, into his mouth and pass them out through his nose.
59
It takes twice as long to lose new muscle if you stop working out than it did to gain it.
127
The average person's skin weighs twice as much as their brain.
131
The average sperm cell swims at 8 inches per hour.
76
Women have about four times as many foot problems as men; lifelong patterns of wearing high heels often are the culprit.
111
One human hair can support 3 ounces.
191
An average heart beats 100,000 times a day, pumping some 2,000 gallons of blood through its chambers. Over a 70-year life span, that adds up to more than 2.5 billion heartbeats.
73