The Vagus Nerve “the Wanderer”

‘Cranial nerve 10 aka the Vagus Nerve is a nerve named after the Latin word, Vagus which means ‘wandering. This nerve is named as such because it originates in the medulla part of the brain stem, then winds on down through the body, networking the brain with the stomach and digestive tract, the lungs, heart, spleen, intestines, liver and kidneys, not to mention a range of other nerves that are involved in speech, eye contact, facial expressions and even your ability to tune in to other peoples voices.

80% of the vagus neurons are sensory, as they report back to your brain (afferent signals,) the status of your organs.

The vagus nerve is a major parasympathetic nerve. The PNS or parasympathetic Nervous system is what helps keeps us sane, well feed, and helps us to recuperate and heal our bodies. The PNS is the opposite of the sympathetic nervous system or SNS which is also known as the fight or flight system, whereas the PNS is the Wine and Dine system. 

Each of us is said to have a certain Vagal tone. The strength of our tone is measured in how quickly our body can relax after stress. The stronger your vagus activity or tone, the faster your body response into a relaxed state, after a stressor. 

Vagal Tone or VT is the strength of your vagus response

VT can be determined by using an electrocardiogram to measure heart rate. HRV stands for heart rate variability

High vagal tone makes your body better at regulating blood glucose levels, reducing the likelihood of diabetes, stroke and cardiovascular disease. 

Low vagal tone, however, has been associated with chronic inflammation. As part of the immune system, inflammation has a useful role in helping the body to heal after an injury, for example, but it can damage organs and blood vessels if it persists when it is not needed.

Evidence of a role for the vagus in a range of chronic inflammatory diseases, including rheumatoid arthritis, Tracey and his colleagues wanted to see if it could become a possible route for treatment. 

Vagal tone

The tone of the vagus nerve is key to activating the parasympathetic nervous system. Vagal tone is measured by tracking your heart-rate alongside your breathing rate. Your heart-rate speeds up a little when you breathe in, and slows down a little when you breathe out. The bigger the difference between your inhalation heart-rate and your exhalation heart-rate, the higher your vagal tone. A higher vagal tone means that your body can relax faster after stress.

What is a high vagal tone associated with?

High vagal tone improves the function of many body systems, causing better blood sugar regulation, reduced risk of stroke and cardiovascular disease, lower blood pressure, improved digestion via better production of stomach basic and digestive enzymes, and reduced migraines. 

Higher vagal tone is also associated with better mood, less anxiety, and more stress resilience. One of the most interesting roles of the vagus nerve is that it essentially reads the gut microbiome and initiates a response to modulate inflammation based on whether or not it detects pathogenic versus