What is the vagus nerve and what does it do?
Polyvagal Theory, developed by Dr. Stephen Porges, states that the autonomic nervous system plays a crucial role in emotional regulation, social connection, and adaptive responses to stress.
And the autonomic nervous system is governed by the vagus nerve.
Let’s explore that in more detail, and how emotional regulation is at the root of most of our mental and physical health concerns.
Forgive me if this gets a little technical. It’s an area of special interest to me which means I can get a bit overexcited and verbose. Bear with!
What is the autonomic nervous system
The autonomic nervous system (ANS) is a critical component of the peripheral nervous system that regulates involuntary physiological processes. It operates largely outside of conscious control and is responsible for managing body functions such as heart rate, digestion, respiratory rate, and sexual arousal.
The ANS is divided into three primary branches:
Sympathetic Nervous System (SNS): Often referred to as the "fight or flight" system, the SNS prepares the body to respond to perceived threats or stressors. It increases heart rate, dilates airways, and inhibits digestive processes to prioritise energy and resources, diverting blood to our arms and legs, readying us for action.
Parasympathetic Nervous System (PNS): Often known as the "rest and digest" system, the PNS promotes relaxation and recovery after a stress response. It conserves energy, slows the heart rate, and stimulates digestive processes to support restoration and healing. This is further split into the ventral vagal complex and the dorsal vagal complex.
Enteric Nervous System (ENS): Sometimes considered a "second brain," the ENS governs the gastrointestinal system and operates independently but can communicate with both the SNS and PNS. It plays a significant role in the digestion of food and the regulation of bowel movements.
The balance between these branches is vital for maintaining overall health and wellbeing. Dysregulation of the ANS can lead to various physical and emotional issues, including anxiety, depression, and chronic health conditions. Concerns like IBS, chronic fatigue, inflammation can be related to an ANS that is not working effectively and has become inflexible. Meaning we aren’t shifting between the different states very easily.
Understanding how the ANS functions can be an essential step in supporting mind-body healing and addressing trauma through a somatic approach.
Polyvagal introduces the concept of three neural circuits that influence behaviour and physiological responses: the ventral vagal complex, the sympathetic nervous system, and the dorsal vagal complex.
All of which are governed by the vagus nerve also known as the 10th cranial nerve.
Ventral Vagal Complex: This pathway is associated with calm states and social engagement. It promotes feelings of safety and the ability to connect with others, facilitating communication and social interactions.
Sympathetic Nervous System: This system prepares the body for 'fight or flight' responses during perceived danger. It leads to heightened arousal levels and readiness for action, which can be beneficial in short bursts but detrimental if prolonged.
Dorsal Vagal Complex: This pathway is linked to the 'shutdown' response. In situations of extreme threat or danger, it can trigger a state of immobilisation, leading to withdrawal or dissociation as a means of self-protection.
Polyvagal Theory emphasises the importance of understanding how these systems interact and how they can influence our behaviours, emotional states, and social functioning.
It has applications in various fields, including psychology, trauma therapy, and even in understanding social dynamics and interactions. This model helps to explain experiences such as anxiety, depression, and trauma responses by highlighting the physiological processes that underlie these emotional states.
About the Vagus Nerve
The vagus nerve is one of the twelve cranial nerves and is the longest nerve in the body. It extends from the brainstem, connecting the eyes, ears, throat, and down to the abdomen, branching out to various organs, including the heart, lungs, and digestive tract.
The vagus nerve plays a critical role in the autonomic nervous system, particularly in regulating the parasympathetic response, which is often referred to as the "rest and digest" state.
This nerve is instrumental in stimulating the body into a stress response and calming the body afterwards. It is involved in functions such as heart rate regulation, respiratory control, and promoting gastrointestinal motility. Somatic exercises are designed to tone the vagus nerve.
This toning can be thought of as similar to toning or training a muscle; a well-toned vagus nerve can help reduce anxiety and stress levels, as it becomes more flexible and responsive, instead of being stuck in one state for too long.
The Vagal Brake
This bit does get a little technical.
The vagal brake is a mechanism by which the vagus nerve helps regulate the body's autonomic functions, specifically in relation to the parasympathetic nervous system.
Think of it like the brake of a car. When we release the brake, the car goes faster. In the context of the vagus nerve, when we release the vagal brake, the sympathetic system is allowed to be more active. Going back to our car analogy, when we press the brake, the car slows down. Similarly, when we activate the vagal brake, the parasympathetic state comes online more, soothing and relaxing us.
To function optimally, the body is constantly balancing the amount of brake we have on at any given time. We actually need less brake in some instances, such as when we do intense exercise, or have to perform at a high level. In those circumstances a little bit of sympathetic activation is essential to give us the energy we need to do the task.
Problems occur when we lose nervous system flexibility. Our brake is either not working, meaning we are trapped in a sympathetic response, often feeling hypervigilant, on edge, angry or irritable. Or our brake is stuck on, keeping us depressed, energy-less, sad, and withdrawn.
In somatic therapy, movement and coaching, understanding the function of the vagus nerve can be beneficial for healing trauma and chronic anxiety. By engaging the vagus nerve, we can promote a sense of safety and resilience in the nervous system, facilitating a deeper connection between mind and body.
If you are interested in working with me either one to one or small group work, check out my therapy and workshop pages. Drop me an email to book a free 20 minute consultation to discuss your concerns and how I can help you.
