Yawns are more contagious among people with closer relationships.
163
The largest cell in the human body is the female egg and the smallest is the male sperm.
682
It takes twice as long to lose new muscle if you stop working out than it did to gain it.
127
Oxygen, carbon, hydrogen and nitrogen make up 90% of the human body.
118
Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18
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
Dogs can be trained to identify the scent of lung cancer long before symptoms develop.
190