It takes about 20 seconds for a red blood cell to circle the whole body.
102
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
Our eyes are always the same size from birth, but our nose and ears never stop growing.
266
Women have about four times as many foot problems as men; lifelong patterns of wearing high heels often are the culprit.
111
The average person's skin weighs twice as much as their brain.
131
The human brain doesn't stop developing until about 25 years old.
102
For most people, no matter how hard you pinch the skin on your elbow with your fingers it doesn't hurt.
515