Stress can result in more headaches as a result of the body rerouting blood flow to other parts of the body.
92
Yawns are more contagious among people with closer relationships.
163
It takes about 20 seconds for a red blood cell to circle the whole body.
102
Our eyes are always the same size from birth, but our nose and ears never stop growing.
266
For most people, no matter how hard you pinch the skin on your elbow with your fingers it doesn't hurt.
515
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
If your DNA was stretched out it would reach to the moon 6,000 times.
256