Your thumb is about the same size as your nose.
124
Coughing can cause air to move through your windpipe faster than the speed of sound - over a thousand feet per second!
197
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
Your body is creating and killing about 2.4 million red blood cells per second.
17
Poor eyesight (myopia) is associated with higher IQ.
232
The largest cell in the human body is the female egg and the smallest is the male sperm.
682
After age 30, the brain begins to lose about 50,000 neurons per day - shrinking the brain .25% each year.
55