Most of the time, though, our breathing is on automatic and we don't think about it. We humans have some breathing problems, probably because of this part-time conscious control over our breathing. We can easily learn to adjust or modify our breathing, just as singers, actors, and instrument players do. The problems come when we learn the wrong things, which don't have bad effects immediately but eventually become bad habits that create the symptoms of anxiety. The balloons are emptied and filled not in response to their own actions, but in response to the actions of the entire torso, which encloses the lungs.
Breathing takes place through the air passages leading from the nose and mouth into the lungs.
Although the bronchial tubes and lungs are lined with smooth muscles that regulate the flow of air, these are not the muscles with which we breathe. The diaphragm should be the main muscle of breathing, because its location in the body gives it the most room to move in a piston-like fashion. Below it are the soft organs and the belly, which can expand outward when a deep breath is needed. Above the diaphragm are the lungs, which are also soft and pliable. The easiest way to understand how the diaphragm works is to make a relaxed, inverted bowl, with the tips of your fingers just interlocking.