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
Dogs can be trained to identify the scent of lung cancer long before symptoms develop.
190
It takes twice as long to lose new muscle if you stop working out than it did to gain it.
127
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
Oxygen, carbon, hydrogen and nitrogen make up 90% of the human body.
118
When you get goosebumps and your hair stands, the hair helps to trap air, making you feel warmer by keeping in your body heat.
46