Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18
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
All the chemicals in a human body combined are worth about 6.25 euro (if sold separately).
266
The adult human brain weighs about 3 pounds (1,300-1,400 g).
99
Your thumb is about the same size as your nose.
124
Stress can result in more headaches as a result of the body rerouting blood flow to other parts of the body.
92
Women have about four times as many foot problems as men; lifelong patterns of wearing high heels often are the culprit.
111