Where is the vagus nerve?
The vagus nerve is comparable in size to the spinal cord. In latin it’s name means “wanderer” because of the vast area that it covers. It’s so important because it is the epicenter of the mind-body connection.
It controls the autonomic nervous system - this is how our stress physiology changes when we face demands or step outside of our comfort zone. The vagus nerve plays a key role in regulation and stress resilience.
It originates in the medulla oblongata of the brainstem. This lies at the base of the brain and the top of the spinal cord. The vagus nerve is divided into two distinct pathways, known as the ventral vagus and the dorsal vagus. They run down into the chest and are separated by their individual roots at the diaphragm - this separates the lungs and abdominals.
The dorsal vagus influences the organs beneath the diaphragm, especially the gastrointestinal system. The ventral vagus innervates the heart and the lungs, and also forms the Social Engagement System. The Social Engagement System is created between the cranial nerves to do with communication and speech, listening and facial expression, as well as the branch of the vagus nerve running from the heart to the face.
The ventral vagal therefore influences our heart rate, breathing rate and also how we connect to others through our tone of voice and facial expression.
Besides giving some output to various organs that regulate them, the vagus nerve comprises between 80% and 90% of sensory fibres that run from the body to the brain. This gives important information about the state of the body's organs to the brain.
The vagus nerve changes all systems depending upon which of it’s pathways are activated: the cardiovascular, digestive, musculoskeletal, immune and endocrine systems all change with stress. So the vagus nerve isn’t really one nerve, it has different pathways and connections.
The vagus nerve
The vagus nerve plays a key role is stress physiology.
What does the vagus nerve do?
When the vagus nerve is functioning well it means that you can fine tune the amount of energy that you allow into your nervous system – so if you want to meet a challenge you can let a little bit more energy in by inhibiting it. This brings attention regulation and it brings focus. Then when it’s over, you can engage more of it and calm your physiology back down. A healthy vagus nerve functions this way and this is what makes us flexible and adaptable.
Following periods of chronic and traumatic stress, the vagus nerve may be interrupted from its job of regulating your nervous system and you may spend more time in fight-flight-freeze. This can take a toll on your psychological health.
A healthy vagus nerve is essential for both your physical and your psychological well-being
What we’re seeing more and more come out in the science now is how the information sent from the body, for example our gut, is impacting psychological well-being. Science is showing how the signals of the heart and their electrical impulses change what’s happening in the brain.
Finally we know that there’s a specific pathway that leads to a reduction of inflammation that can lie at the heart of many chronic issues like pain, depression and gut health. When the vagus nerve is working well inflammation decreases because it reduces what’s called inflammatory cytokines.
Vagus nerve disorders, or low vagal tone, can arise following periods of chronic or traumatic stress. It can lead to things like:
gastrointestinal issues such as irritable bowel syndrome, chronic constipation and diarrhoea.
it may lead to things like a racing heart or hypertension.
it may impact on the immune system causing allergies, asthma or autoimmune issues.
it may cause musculoskeletal issues, chronic pain or fibromyalgia.
it can cause headaches or migraines
it may lead to insomnia
it may cause anxiety or an inability to relax and switch off
it may cause chronic fatigue, extreme procrastination and flatness.
Hope lies in knowing that the vagus nerve’s functioning can be improved by using powerful, evidence-based tools and resources. These are like doing bicep curls for your vagus nerve and in time, you’ll become more flexible, adaptable and resilient when you face stressors.
Your physical and psychological well-being will improve, and so will the health of your professional and personal relationships.
Want to learn more about how to improve the tone of your vagus nerve? The Vagus Nerve Masterclass teaches you how.