The vagus nerve is the 10th of the 12 cranial nerves, and the longest. It’s technically a pair of vagus nerves, stretching from the lower part of the brain stem (medulla oblongata) and travelling down both sides of the neck, all the way to the colon. The word “vagus” is Latin for “wanderer”, which describes how the vagus nerve stretches around the body, with nerve branches connecting to the gut, liver, heart and lungs.
Often referred to as an “information superhighway”, the vagus nerve is one way the body and brain communicate. The vagus nerve is both efferent and afferent, which means it sends signals from the body to the brain, and vice versa, from the brain to the body. Eighty per cent of its nerve fibres communicate from the body up to the brain, while only 20 per cent from the brain to the body.
The vagus nerve plays an important role in the body as it’s the main parasympathetic nerve, influencing breathing, digestion, heart rate, mood, immune function and reflex actions. The vagus nerve switches off your sympathetic nervous system’s fight or flight response, allowing you to move into a regulated calm state, often referred to as your “rest and digest” state.
