Your thumb is about the same size as your nose.
124
Oxygen, carbon, hydrogen and nitrogen make up 90% of the human body.
118
The adult human brain weighs about 3 pounds (1,300-1,400 g).
99
The average sperm cell swims at 8 inches per hour.
76
Every year your body replaces 98% of your atoms.
119
Yawns are more contagious among people with closer relationships.
163
After age 30, the brain begins to lose about 50,000 neurons per day - shrinking the brain .25% each year.
55
Your body is creating and killing about 2.4 million red blood cells per second.
17