The average sperm cell swims at 8 inches per hour.
76
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
Your heart will pump about 212 million liters in its lifetime.
26
Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18
The adult human brain weighs about 3 pounds (1,300-1,400 g).
99
Your body is creating and killing about 2.4 million red blood cells per second.
17
One human hair can support 3 ounces.
191