Yawns are more contagious among people with closer relationships.
163
When you take a step, you are using up to 200 muscles.
886
Your body is creating and killing about 2.4 million red blood cells per second.
17
Oxygen, carbon, hydrogen and nitrogen make up 90% of the human body.
118
Stress can result in more headaches as a result of the body rerouting blood flow to other parts of the body.
92
It takes about 20 seconds for a red blood cell to circle the whole body.
102
Your heart will pump about 212 million liters in its lifetime.
26