Yawns are more contagious among people with closer relationships.
163
The largest cell in the human body is the female egg and the smallest is the male sperm.
682
If every muscle in your body could pull in one direction, you could lift nearly 25 tons.
22
The average sperm cell swims at 8 inches per hour.
76
Staying awake for 17 hours is the same for your body as drinking 2 glasses of wine.
193
The human brain is very soft, having a consistency similar to soft gelatin or firm tofu.
13
The human body contains over a billion miles of DNA.
147