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2nd in a group of mini-episodes that are supposed to be limited to 5 minutes. Go figure, this one on the basics of the anatomy associated to the Ventral Vagal Complex broke the rules and comes in at 12 minutes. So it goes. Show Notes Page with with additional commentary.
Many of us think of the Polyvagal theory as challenging. Understandably so, it’s kinda complex. That’s necessary and appropriate for what it is, namely: a parsimonious theory that explains a multidude of phenomena with a simpler, more elegant explanation than what science had found before.
3 cheers for Stephen Porges for having changed history and opened up an entirely new understanding of ourselves and the general goings on in evolution. Unfortunately to pull that off requires some pretty big words and that can confuse us.
Here’s my prediction. Soon enough it’ll be completely commonplace in our lexicon and we’ll rattle off phrases like Nucleus Ambiguous or Ventral Vagal Complex as though we always knew them. Soon enough.
In the meantime let’s name the major physical attributes about this newest branch of the Autonomic Nervous System (both in our understanding and in terms of phylogenetic or evolutionary origin).
The VVC or Ventral Vagal Complex is a collection of associated neurological and anatomical structures in our body. It so happens that all of the muscular and visceral components that allow us to socially engage; breath, eat and speak at the same time; and keep calm while in close proximity to others we find trustworthy (a new mammalian capacity that didn’t exist before 60 million years ago) are connected by nerves that make them all work together. .
While the a study of all of this can go very deep with gradually more complex levels of distinction, a great place to start is by simply naming the anatomy that is included in this system and think about what these structures do for us.
It’s also helpful to recognize that these anatomical structures are all tied together in a “complex”, joined by specific kinds of nerves that are all very fast in their transmission of information and ultimately connect through the central “hub” of the VVC, the Nucleus Ambiguous -NA (ambiguous by name and by dent that it is difficult for scientist to isolate and clarify the boards of these nerve nuclei, not because the system doesn’t know what it’s doing).
Innervated by these super fast nerves (fast due to their myelinated sheath that helps their signal run faster along the path) is all the stuff in us that allows us to be social, like:
- Muscles of the Face. – For expressing emotion and signaling our experience to others.
- Muscles of the middle ear. – For tuning the ear to the frequency of the human voice so as to hear one another instead off all the other noise in the environment.
- Muscles of the eyes and eye lids. – For emotional communication, seeing and orienting.
- Muscles of mastication. – Basically for eating but think of our eating as a social species as a basically a social act where we often eat and speak together at the same time.
- Muscles of the neck. – Most commonly referenced for this is the sterno-cliado-mastoid muscle that turns our heads left and right for orienting to new sounds and shadows, but head bobbing is also included in this.
Additionally the VVC has major influence over the supra-diagphramatic organs like:
- The heart or more specifically the sino-atrial node that acts as the pacemaker of the heart. – Active VVC influence on the “vagal break” brings the heart into a dynamic rhythm and frequency and relationship with the breath and aids to the feeling of well-being and sense of safety (i.e. A calm heart).
- The lungs. – VVC influence here helps us maintain oxygenation while doing complex tasks like talking and swallowing (i.e. Easy to breath).
- The Larynx and Pharynx. – These help with vocalization as we expel air in good coordination with the lungs when they are innervated by the VVC (i.e. Easy to speak with variation in tone and not loose breath).
- Esophageal muscles. – For the smooth and easy swallowing (i.e. Makes eating much more pleasurable).
Since these structures are all tied together by nerves that are all associated through the NA, to stimulate one of them is to stimulate all of them. They work in a “complex.” Which is massively important to us clinically but also just really phenomenally cool to think about generally.
From here there is incredible depth to be found by investigating the inner workings of this Ventral Vagal Complex and its interrelationship with other subsystems of the autonomic nervous system.
In the next mini-episode we’ll take a short look at the Sympathetic Nervous System and its major attributes.