Eli5: Why can’t we continually go back to sleep when we wake up ? What happens in our brain that says it’s fully rested and doesn’t need any more?

Question

Eli5: Why can’t we continually go back to sleep when we wake up ? What happens in our brain that says it’s fully rested and doesn’t need any more?

In: Biology

Answer 1

To oversimplify stuff. There’s a chemical in your brain that when reaches certain level triggers “go to sleep” protocol. When you sleep this chemical is being flushed. When your brain is done it releases another chemical saying “don’t sleep now” and you wake up. There’s also a bunch of other factors like circadian rhythm, light also plays a role, so it’s not that simple. But yeah. Basically chemical signals.

Answer 2

Actually you have it backwards, your brain produces a chemical called “melatonin” when it’s tired and doesn’t when it isn’t.