WHAT HAPPENS DURING SLEEP
When you go to sleep at night, your body gets the rest it needs and the time it needs to repair itself and get ready for another day. Hard-working body cells that are worn out from a long day of activity are repaired and replaced. New energy is stored up for the next day. Your heart keeps beating, but at a slower pace as your breathing slows. Your blood continues to be pumped throughout your body, giving cells the food and oxygen they need.
When you are awake, your brain must pay attention to the outside world. During sleep, the brain finally gets to take a rest. Your eyes close so that you don't take in any information that the brain would have to process. Your brain stays active, but you are no longer aware of yourself or what is going on around you.