Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18
It takes about 20 seconds for a red blood cell to circle the whole body.
102
Your body is creating and killing about 2.4 million red blood cells per second.
17
After age 30, the brain begins to lose about 50,000 neurons per day - shrinking the brain .25% each year.
55
If you are cold you are more likely to be hungry because you use energy to keep warm.
143
The human brain doesn't stop developing until about 25 years old.
102
Our Right Lungs takes more air than our left lung.
194