The vagus nerve (cranial nerve X) has two components to it linking to both of our autonomic nervous systems; the sympathetic nervous system and the parasympathetic nervous system. When we are under stress, we are in a state called Fight or Flight which is where our sympathetic nervous system comes in. The nerves impacting the sympathetic nervous system come primarily from the thoracic vertebral column or the mid back.
When we are calm and relaxed we fall into what’s called the parasympathetic nervous system; which nerves come primarily from the head and neck and sacral regions. In this state our body is able to heal and digest our food. Also, we can think clearly and not be as reactive to stimuli as blood leaves the amygdala (fear center of the brain) and goes back to the frontal lobe of the brain.
When we take deep breaths cortisol levels (stress hormone) decrease, and systolic and diastolic blood pressure is improved along with stress.1
Even though this systematic review along with a host of other studies showing the benefit of deep diaphragmatic breathing doesn’t specifically talk about the vagus nerve, we can know that the vagus nerve is involved as it controls these two sides of our autonomic nervous system. When the vagus nerve is stimulated our body calms down and allows for healing to occur. Which is what we all want I think. Although, stress inhibits vagus nerve stimulation which makes it near impossible to heal and be well.
1. Hopper, S. I., Murray, S. L., Ferrara, L. R., & Singleton, J. K. (2019). Effectiveness of diaphragmatic breathing for reducing physiological and psychological stress in adults: a quantitative systematic review. JBI database of systematic reviews and implementation reports, 17(9), 1855–1876.
Till next time. Thank you,