The human brain doesn't stop developing until about 25 years old.
102
Every year your body replaces 98% of your atoms.
119
The largest cell in the human body is the female egg and the smallest is the male sperm.
682
When you take a step, you are using up to 200 muscles.
886
An average heart beats 100,000 times a day, pumping some 2,000 gallons of blood through its chambers. Over a 70-year life span, that adds up to more than 2.5 billion heartbeats.
73
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