Yawns are more contagious among people with closer relationships.
163
The human brain uses approximately as much energy as a 10 watt light bulb.
120
Your thumb is about the same size as your nose.
124
For most people, no matter how hard you pinch the skin on your elbow with your fingers it doesn't hurt.
515
It takes about 20 seconds for a red blood cell to circle the whole body.
102
The human brain is very soft, having a consistency similar to soft gelatin or firm tofu.
13
The average sperm cell swims at 8 inches per hour.
76
After age 30, the brain begins to lose about 50,000 neurons per day - shrinking the brain .25% each year.
55