Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18
Your body is creating and killing about 2.4 million red blood cells per second.
17
Enamel is hardest substance in the human body.
61
If you are cold you are more likely to be hungry because you use energy to keep warm.
143
When you get goosebumps and your hair stands, the hair helps to trap air, making you feel warmer by keeping in your body heat.
46
The human brain has the capacity to store everything that you experience.
4k
The adult human brain weighs about 3 pounds (1,300-1,400 g).
99