The adult human brain weighs about 3 pounds (1,300-1,400 g).
99
Poor eyesight (myopia) is associated with higher IQ.
232
Oxygen, carbon, hydrogen and nitrogen make up 90% of the human body.
118
Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18
It takes about 20 seconds for a red blood cell to circle the whole body.
102
The average sperm cell swims at 8 inches per hour.
76
One human hair can support 3 ounces.
191
Yawns are more contagious among people with closer relationships.
163