Enamel is hardest substance in the human body.
61
The adult human brain weighs about 3 pounds (1,300-1,400 g).
99
It would take about 1,200,000 mosquitoes to fully drain the average human body of blood.
217
Oxygen, carbon, hydrogen and nitrogen make up 90% of the human body.
118
The largest cell in the human body is the female egg and the smallest is the male sperm.
682
Chewing gum boosts your brain power.
285
The average person's skin weighs twice as much as their brain.
131
Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18