It takes about 20 seconds for a red blood cell to circle the whole body.
102
It would take about 1,200,000 mosquitoes to fully drain the average human body of blood.
217
The largest cell in the human body is the female egg and the smallest is the male sperm.
682
Dogs can be trained to identify the scent of lung cancer long before symptoms develop.
190
Women have about four times as many foot problems as men; lifelong patterns of wearing high heels often are the culprit.
111
If every muscle in your body could pull in one direction, you could lift nearly 25 tons.
22
Yawns are more contagious among people with closer relationships.
163
The adult human brain weighs about 3 pounds (1,300-1,400 g).
99