Markham Heid, ‘Science Confirms That the Vagus Nerve Is Key to Well-being’, https://elemental-medium-com.cdn.ampproject.org/c/s/elemental.medium.com/amp/p/c23fab90e211, Elemental, Medium (Dec 19 2019)
Reach for the ceiling and stretch your limbs. Each of these simple acts bestows a sense of calm and comfort. And each works its soothing magic in part by activating a complicated system of nerves that connects the brain to the heart, the gut, the immune system, and many of the organs. That system is known collectively as the vagus nerve. (…) The vagus nerve, also called the “10th cranial nerve,” is the longest, largest, and most complex of the cranial nerves, and in some ways it’s also the least understood. (…) Vagus is Latin for “wandering,” which is apt when one considers all the different parts of the body the vagus nerve reaches. (…) It seems like every year somebody finds a new organ or system that it talks with. (…) There’s a massive bioelectrical and biochemical series of events that the vagus nerve is responsible for, and all that is almost impossible to map. (…) We know that depressed people have low vagal activity, and this is associated with less intonation and less-active facial expressions. (…) While some aspects of vagal activity are inscrutable, it’s clear that the nerve is the governor of the parasympathetic nervous system, which helps control the body’s relaxation responses. In simple terms, heightened vagal activity counteracts the stress response, which involves the sympathetic nervous system. (…) The sympathetic nervous system is fight or flight, while the parasympathetic nervous system is more chill out. (…) Pick almost any common medical condition that’s made worse by stress or inflammation — everything from arthritis to inflammatory bowel disease — and there’s research showing that vagus nerve stimulation can help treat it or relieve its symptoms. (…) Doctors are exploring the use of vagus nerve stimulation for a wide range of diseases and disorders, including afflictions of the mind. (…) More and more, we’re learning how critical vagal activity is to attention and mood.