Your thumb is about the same size as your nose.
124
Your heart will pump about 212 million liters in its lifetime.
26
Enamel is hardest substance in the human body.
61
Dogs can be trained to identify the scent of lung cancer long before symptoms develop.
190
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