The vagus nerve connects the brain to the body. Its primary function is to activate our parasympathetic nervous system. There are two branches of the nervous system—1) the parasympathetic nervous system (PNS), also known as “rest, digest, and heal”; and 2) the sympathetic nervous system (SNS), or “fight and flight."
It runs from the brainstem through the neck and down to your abdomen, innervating your lungs, heart, esophagus, and the majority of your abdominal organs.