Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18
One human hair can support 3 ounces.
191
After age 30, the brain begins to lose about 50,000 neurons per day - shrinking the brain .25% each year.
55
The average sperm cell swims at 8 inches per hour.
76
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
The largest cell in the human body is the female egg and the smallest is the male sperm.
682
Dogs can be trained to identify the scent of lung cancer long before symptoms develop.
190