The medulla is a part of the brainstem and is vital to the essential well-being of the organism. In this very small and compact portion of the brain where the centers for respiration and pulse are housed. In a very simple sense the circuitry for these centers is an on / off affair. You breathe in, you breathe out. Your heart contracts in systole and relaxes in diastole. When these activities cease, so do you.
The rest of the brain is a very complicated circuitry. In our busy world this circuitry can be overloaded by multiple inputs, multi-tasking, conflicting demands, a hectic schedule, phone calls, instant messaging, music playing, parents yelling, teachers demanding, siblings fighting, etc., etc., etc..
It is at times like these that the medulla can be your friend. Provide yourself some quiet time andconcentrate on the simple on / off circuitry of your breathing. You will find a readily availableretreat from the "chatter" of our world.
You may call this meditation or relaxation or whatever you like. Regardless, the medulla is always available to provide you a release from overwhelming input.