The human nervous system is separated into two branches: the sympathetic (responsible for the "fight-or-flight response") and the parasympathetic (responsible for the "relaxation response"). The vagus nerve is a major parasympathetic nerve that meanders and branches through the body, from the anterior brain through the esophagus, trachea, heart, diaphragm, stomach, and intestines. It is directly responsible for slowing respiration, reducing heart rate, lowering blood pressure, and stimulating digestive activity.
Because the vagus nerve runs through the diaphragm (the dome-shaped rubber band located under the lungs), we can directly access it by manipulating the diaphragm. Diaphragmatic breathing massages and stimulates the vagus nerve, sending messages to the brain that everything is okay. This is why we feel calmed when we sigh or breathe deeply. So for a quick fix to stress, diaphragmatic breathing instantly elicits the relaxation response, slowing the heart rate, lowering blood pressure, and stimulating digestion and metabolism.
However, most of us normally breathe shallowly in the upper chest, moving the diaphragm very little. This stimulates the sympathetic nervous system, invoking the "fight-or-flight response." So, when we are nervous or stressed and we either hold our breath or breathe shallowly, we exacerbate the tension in our bodily systems in a vicious cycle. If we retrain our habits and remember to breathe diaphragmatically on a daily basis and particularly at stressful moments, we will feel peaceful and will enjoy profound benefits to our overall health. |
