Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18
If you are cold you are more likely to be hungry because you use energy to keep warm.
143
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
Oxygen, carbon, hydrogen and nitrogen make up 90% of the human body.
118
The adult human brain weighs about 3 pounds (1,300-1,400 g).
99
If every muscle in your body could pull in one direction, you could lift nearly 25 tons.
22