It takes about 20 seconds for a red blood cell to circle the whole body.
102
Stress can result in more headaches as a result of the body rerouting blood flow to other parts of the body.
92
The average sperm cell swims at 8 inches per hour.
76
If every muscle in your body could pull in one direction, you could lift nearly 25 tons.
22
Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18
Oxygen, carbon, hydrogen and nitrogen make up 90% of the human body.
118
If you are cold you are more likely to be hungry because you use energy to keep warm.
144