The human brain doesn't stop developing until about 25 years old.
102
One human hair can support 3 ounces.
191
If every muscle in your body could pull in one direction, you could lift nearly 25 tons.
22
Your thumb is about the same size as your nose.
124
The average sperm cell swims at 8 inches per hour.
76
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