Yawns are more contagious among people with closer relationships.
163
Stress can result in more headaches as a result of the body rerouting blood flow to other parts of the body.
92
The human brain uses approximately as much energy as a 10 watt light bulb.
120
Enamel is hardest substance in the human body.
61
It takes twice as long to lose new muscle if you stop working out than it did to gain it.
127
Oxygen, carbon, hydrogen and nitrogen make up 90% of the human body.
118
Dogs can be trained to identify the scent of lung cancer long before symptoms develop.
190
Your thumb is about the same size as your nose.
124