Enamel is hardest substance in the human body.
61
Coughing can cause air to move through your windpipe faster than the speed of sound - over a thousand feet per second!
197
Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18
It would take about 1,200,000 mosquitoes to fully drain the average human body of blood.
217
After age 30, the brain begins to lose about 50,000 neurons per day - shrinking the brain .25% each year.
55
One human hair can support 3 ounces.
191
Yawns are more contagious among people with closer relationships.
163
The human brain doesn't stop developing until about 25 years old.
102