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Introduction to the Autonomic Nervous System

Updated: Mar 2

Three Branch System Thanks to recent developments in the understanding of human physiology contributed by Dr. Stephen Porges, Dr. Peter Levine and others, we have a more nuanced way to talk about how embodiment and safety work. Life has some crazy stuff in it. Some of it is beautiful and feels great, some of it is horrible and takes a serious toll on us. Our bodies have evolved to respond to the various situations of life in order to keep us surviving if not thriving. Along with the rest of the mammal kingdom we have three main branches of our Autonomic Nervous System (ANS) -aka- 'operating modes' for dealing with the challenges that life throws at us. Each of these operating modes rely on particular fibers of our nervous system in order to help us do the behaviors that keep us safe. Here is a brief outline of these three different parts of our nervous system.

Ventral Vagal - The Social Connection System

The first one, which you can think of as green, prepares our physiology to find safety by connecting with other people. Our face and our voice show our emotions while we are also able to interpret others' inner world by what we see and hear from them. When this part of our nervous system has the wheel so to speak we can think creatively, take in new information, and express ourselves relatively freely. We can feel close and connected and our body feels some sense of rightness or pleasure in being alive and present.

Sympathetic - The Get Sh*t Done System

You can think of the second operating mode as yellow. When this part of our nervous system turns on our bodies are getting ready to DO things. This could be focusing on a test or driving a vehicle, it could be exercising or having a tough conversation, this could also be getting ready to defend ourselves or run away. In this state, we can feel excited or frustrated or anxious, our muscles tense up ready for action (even though there might not be any action this time,) our heart rate and breath rate increase and we may become more vigilant to sounds or movements or people. As you can imagine this part of our nervous system is really helpful - both in moments of danger as well as 'normal' everyday activities. However it can cause us excess stress and ongoing hyper-vigilance if it stays on for too long.

Dorsal Vagal - The Energy Conservation System

The third part of our threat response system is blue. Just kidding it's red. When this part of our physiology takes over it's usually because the green and the yellow weren't able to finish the job and our system needed some more support. This part of our system comes in to make things softer, slower, and simpler. We may become really tired or s p a c e y , we can begin to loose touch with our sense of being here, things might also start to feel less intense or even less real. Our heart rate and breath rate slow down and our body begins to turn inward and conserve energy. This part of our nervous system is also essential - it helps us to put the brakes on when things get too intense and protects us from feeling overwhelmed for too long. Once again though, when our body develops a habit of using this branch of the nervous system it can also cause challenges like chronic fatigue, or a life that feels like we are just going through the motions.

Recap & Self Study

As you can see each of these three branches of our ANS is really important and at times they all have their essential roles to play. Things get tricky when the yellow or red get stuck 'on' for too long or become too easily activated. That's when life starts to feel like a battleground that we have to fight our way through or like a monotonous ordeal that drains us of our vitality. The good news is that you can help your body and brain literally rewire and learn how to have more of the green stuff happening more often while letting the yellow and red work their magic as needed.

Which of these three branches sound the most familiar to you? Do you recognize yourself in any of the above descriptions? Thinking back to a recent time when you were under a mild amount of stress and recalling how you responded can be one way to begin to track your autonomic nervous system habits. If you enjoyed this introduction to the autonomic nervous system you can also find a free quiz here that helps you to map our your nervous system profile and learn more about what you can do to begin creating more ways back to the safety and regulation of your ventral vagal system.

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