eli5: How do we wake up?

Question

Like without alarms or any outside sources. We fall asleep cause we are tired. How does the body wake itself up?

In: 12

Answer 1

There is a neurotransmitter called Adenosine that is responsible for making us feel sleepy. This accumulates throughout the day. While you sleep, it is metabolized/ broken down by the body until the levels of it are low enough that your brain stops being sleepy.

There is also a hormone called Melatonin that regulates the rise and fall of your circadian rhythm. This is what keeps your body on a natural schedule, assuming no interruptions from artificial light and alarm clocks…etc