Question: how does our brain automaticly tell our body to do things without us doing anything?

Jess Bean answered on 27 Jun 2013:

The section of our brain that automatically tells our body to do things, like breathe and beat our hearts is called the medulla oblongata and is at the back of your neck. Basically your brain doesn’t trust you to regulate all these things by yourself (imagine if you had to remember to breathe all the time!) so it does it itself. It sends nerve signals between your heart and lungs which loop back to your brain. This makes sure your heart doesn’t beat too fast or anything!