Sleep is absolutely essential for every human being. Despite scientists still not figuring out the process entirely, we still know a lot about this daily activity. Every mammal. bird and most reptiles, amphibians and fish require sleep to function. Here are 16 things you probably never knew about sleep.
1. What goes on when you sleep
Your brain recharges
Your cells repair themselves
Your body releases important hormones
2. You need different amounts of sleep depending on your age: