The nerves inside the body detects the pressure and if the stomach is heavy then it means full.
Actually brain tells to stop eating if you further try to eat and enlarge the stomach the reverse pressure is created and you may vomit the food.
Your brain.
Yes, it does.
It makes chemicals. For example, chemicals from and to the brain and stomach help you to know when you are hungry/full.
That you need to eat to restore energy levels and give your body the required nutrients. As simple as that.
I am hungry
When you are hungry it means that you need to eat. Your body needs fuel to function and when the body needs fuel it sends a signal to the brain, which makes you hungry.
Nerves and brain cells in the brain send electric signals to each other to tell the body what to do.
I think the answer you're looking for is nerves. Nerves are the types of cells that transmit signals from your body to your brain, and brain to your body. Nerve cells release charged molecules in a controlled way to create electrical signals that can propagate information across the body.
what the brain tells you is how to control your functions in your body, how to do school work, how to play, etc.
Your brain is a very hungry organ. It weighs only a 50th of your body weight, yet consumes one fifth of your energy.
the brain helps you to tell you what you hear
they tell your brain what you feel, hear, see, and taste.