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
The human brain doesn't stop developing until about 25 years old.
102
Every year your body replaces 98% of your atoms.
119
It takes twice as long to lose new muscle if you stop working out than it did to gain it.
127
Stress can result in more headaches as a result of the body rerouting blood flow to other parts of the body.
92
Our eyes are always the same size from birth, but our nose and ears never stop growing.
266
Your heart will pump about 212 million liters in its lifetime.
26