It takes about 20 seconds for a red blood cell to circle the whole body.
102
Oxygen, carbon, hydrogen and nitrogen make up 90% of the human body.
118
Enamel is hardest substance in the human body.
61
It takes twice as long to lose new muscle if you stop working out than it did to gain it.
127
Our eyes are always the same size from birth, but our nose and ears never stop growing.
266
The adult human brain weighs about 3 pounds (1,300-1,400 g).
99
Staying awake for 17 hours is the same for your body as drinking 2 glasses of wine.
193
The average person's skin weighs twice as much as their brain.
131