Your thumb is about the same size as your nose.
124
It takes about 20 seconds for a red blood cell to circle the whole body.
102
After age 30, the brain begins to lose about 50,000 neurons per day - shrinking the brain .25% each year.
55
The largest cell in the human body is the female egg and the smallest is the male sperm.
682
Yawns are more contagious among people with closer relationships.
163
The adult human brain weighs about 3 pounds (1,300-1,400 g).
99
It takes twice as long to lose new muscle if you stop working out than it did to gain it.
127
If every muscle in your body could pull in one direction, you could lift nearly 25 tons.
22