The Vagus Nerve & The polyvagal Theory

The Vagus Nerve is my new FAVORITE thing to chat about… and to work with… and to teach… and to use in my own healing journey. When I started learning about the Vagus nerve, it was truly transformational for myself and my clients. Now, I just want to learn more and more. But what is the Vagus nerve and why should you care?

Let’s start with some history….

The Vagus nerve was first found in 1921. It was named the vagus Nerve because the latin term vagus means wandering. The Vagus nerve is the longest nerve in the human body and it wanders from the brain into the organs in the neck, chest and abdomen.  It is also known as the 10th cranial nerve.The vagus nerve transmits signals from the parasympathetic nervous system AKA the Rest and Digest system.  These signals are carried to the heart, lunges and digestive tract. 

The Polyvagal Theory was formulated by Dr. Stephen Porges in 1994 which he developed after his experiments on the vagus nerve. Dr. Porges is an expert in the field and has done much research since then around restoring homeostasis and bringing the nervous system back into its optimal state.

So what exactly does the Vagus Nerve do?

The vagus Nerve is the longest nerve in the Autonomic nervous system.  It is one of 12 cranial nerves that lead from the brainstem into the abdomen. It plays a major role in maintaining homeostasis and regulating the nervous system. It controls the function of many significant organs in the human body such as the heart, lungs and digestive tract.

The Vagus nerve is also one of the main components of the parasympathetic Nervous system and plays a huge role in the immune system, control of mood, digestive system and heart rate.

By stimulating the Vagus nerve you can:

• Decrease heart rate

• Increase digestive activity

• Slow down respiratory rate

• Improve immune function

• improve resiliency

• Improve social engagement

• Improve bowel function and movement

• Improve depression and anxiety

• Boost oxytocin

• Play a role in stimulating cell growth

Two Branches of the Vagus Nerve:

1. Dorsal Vagal System: This system is everything BELOW the diaphragm.  It supplies nerves to  the visceral organs below the diaphragm, including the stomach, liver, spleen, kidneys, gallbladder, urinary bladder, small intestine, pancreas, and ascending and transverse parts of the colon. This system works much slower than the ventral vagal.  In extreme cases of danger there is a surge in dorsal activity which can lead to system shutdown (IE: drop in blood pressure, fainting, state of shock)

2. Ventral Vagal System: This is the system ABOVE the diaphragm. It supplies nerves to the heart, lunges, throat, inner ear and facial muscles.  This is the primary regulator of the heart rate and muscles in the face and hand. This system helps us orient to safety and it has evolved into our social engagement system. Our social Engagement system helps us coexist as mammals, work in community, reproduce and co-regulate. 

What is The Polyvagal Theory?

The polyvagal states that the Vagus Nerve is Split into two distinct parts: ventral vagal system (social engagement) and dorsal vagal system (immobilization) as a function of the parasympathetic nervous system. Both are states of “rest and digest”, although presenting very differently.

The polyvagal theory then has  three guiding principles:

1. Hierarchy of the autonomic nervous system: this states that the nervous system  has three reaction patterns which are activated in a specific order.

2. Neuroception: This is the state of cognition without awareness which is triggered by a stimulus like danger.  This is often thought of by the average person as the feeling of having eyes on the back of your head.

3. Co regulation:  This is a very integral part of our health and happiness as humans. IT is the need to feel safe enough to allow yourself to be in relationships with others which can be difficulty for traumatized people.

The hierarchy of the nervous system has three responses:

1. Ventral Vagal/Safe Zone:  This is when our nervous system feels safe and we do not feel like we are under immediate threat.

2. Fight or Flight response: This is the sympathetic nervous system response. WE experience activation of the sympathetic nervous when a stressor triggers us. This prepares us to fight, or flight  think heart rate increases, digestion decreases and breath rate increases.

3. Freeze or complete immobilization: This is total shutdown mode. This can happen when we are in a severely acute stressful situation or a chronic stressful situation. Our nervous system reduces metabolic output and we can feel number or frozen or not be able to respond or flee

Why is this so important?

The Vagus Nerve is ESSENTIAL for our ability to find homeostasis and regulates the autonomic nervous system.  If the Vagus Nerve is not functioning well, it can lead to a myriad number of health issues including a dysregulated autonomic nervous system. 

Some signs or symptoms of a dysregulated vagus nerve are:

• Abdominal pain and bloating

• Acid reflux

• Changes in heart rate, blood pressure and blood sugar

• Difficulty swallowing or loss of gag reflect

• Dizziness or fainting

• Hoarseness, wheezing or loss of voice

• Loss of appetite, feeling full quickly or unexplained weight loss

• Nausea and vomiting

Vagus nerve dysfunction can also play a role in pain management, chronic pain, stress management and chronic stress which is why I use vagus nerve stimulation techniques with each of my clients.

The vagus nerve regulates homeostasis in our bodies by changing function such as the heart rate and breath rate. Alternatively, we can use breathwork techniques to have an effect on regulating the vagus nerve.

The polyvagal theory is important because it gives us some insight to how the body and brain work together.    The polyvagal theory helps us understand how the ANS responds to cues in our environment as well as sensations and feelings in our bodies. It gives therapists a framework to consider reasons why people act in the ways they do. It also helps us understand the connection between mind and body even better as well.

At the end of the day, this knowledge helps practitioners (psychotherapists, psychiatrists, physical therapists, etc) work WITH their patients more and understand their patients and clients better. On the flip side, it helps YOU understand your reactions to certain situations and understand how to better take care of your mind and body. By learning about the inner workings of our nervous system, we can have profound effects on how we manage stress, manage pain and manage mental health.

In my program Nourish Your Nervous System, we use the knowledge of the vagus nerve, the polyvagal theory and the nervous system to access states of healing. We use your body, breath, self massage and more to stimulate the vagus nerve and put your body into a state of rest and digest. These can be powerful tools especially for someone who has been living in chronic states of pain, discomfort and stress.

What are some useful techniques?

1. Practice Diaphragmatic Breathing: The Vagus Nerve runs through the diaphragm. I could write a whole other blog post on diaphragmatic breathing itself but I will save that for another day. If you’re not practicing already, get on it. It’s a powerful tool in your arsenal. Due to the vagus nerves connection to the diaphragm, by practicing diaphragmatic breathing you are massaging and stimulating the vagus nerve. Add in a little lengthening of your exhale and you are in the sweet spot—- you will be helping put yourself in rest and digest state which will lower heart rate, increase digestion, and put you in a healing state needed post workout, in rehab and beyond!

   Watch a how to below:)

2. Hum or Sing: The Vagus nerve has connection to your larynx and pharynx. Stimulating this area with humming or singing is a really powerful way to stimulate the vagus nerve and self regulate the nervous system. This is why I almost always end my yoga classes with a nice big “Ohm”. It’s an honoring of yoga philosophy and a sneak peek into the power of the Vagus Nerve.

3. Splash Cold Water onto your Face: This is known as the diving reflex. By splashing cold water on the face, you stimulate the trigeminal nerve which in turn stimulates the vagus never thus creating a parasympathetic response.

4. Trigeminal Nerve Stimulation: Similar to splashing water on your face, you can use gently massage techniques on the face to stimulate the trigeminal nerve which feeds back to the vagus nerve. The simplest and easiest is gently rubbing and tapping the entire face. why? the trigeminal nerve is in charge of sensory and motor function in the face. By touching the face, you are stimulating the trigeminal nerve and in turn stimulate the vagus nerve. Watch the video below for more

Personally, I use at least one of these techniques everyday to help regulate my nervous system, my mood and my chronic pain. With clients, I use these techniques before each session to prime and prep the body for a our sessions so we create lasting change. My clients use these techniques to manage chronic pain, chronic stress and chronic illness.

These are only a few of the many techniques I use daily. Stay tuned here, on youtube or on instagram— @dr.kerrymcginn to keep learning more about the vagus nerve. And if you want to take a deep dive— join me for Nourish Your Nervous System— waitlist is open and all the details are coming mid August.