The Autonomic Vervous System has two basic subdivisions (sympathetic and parasympathetic). Both subdivisions interact with the vagus nerve and influence the central nervous system (brain and spinal cord)
The vagus nerve, known as the 10th cranial nerve, is a primary component of the autonomic nervous system, divided into two separate branches, (ventral and dorsal)
These two vagal branches of the ANS deliver information from the body (afferent influences) to the Central Nervous System. (Note: vagus nerve comprises about 80-90% afferent nerves conveying sensory information about the state of the body's organs to the central nervous system)
One pathway is referred to as the Ventral Vagal (front side of the vagus nerve). The other is referred to as the Dorsal Vagal, (back side of the vagus nerve).
Each has its own adaptive, self-protective function, as both inhibit ( put brakes on) the arousal/mobilization activities of the sympathetic division of the ANS, when this division is overactive (state of alarm, mild, moderate or extreme)
Thus, we have both mobilizing and immobolizing strategies built into our self-protecting nervous system.
CONSIDER THE FOLLOWING:
SYMPATHETIC division (of the ANS)
historically known as the "fight or flight" response system, is associated with mobilization such as high arousal, emergency responses
VENTRAL VAGAL BRANCH (of the ANS)
is the most recent evolutionary development and is associated with
lower levels of arousal as displayed during relaxation and
positive social engagement activites
DORSAL VAGAL BRANCH (of the ANS)
is the oldest evolutionary development and is associated with immobilization when we are confronted with real or imagined danger.
It is associated with shutdown and withdrawal from
threat and depressive behaviors
THEY WORK TOGETHER
failitating self-protection and our survival
When we activate the ventral vagal
Relaxation Theapy (RT)
and other calming procedures,
we experience calmness, safety and security. Under non-threatening circumstances, we are emotionally open,
social and connected.
We experience positive sensations,
more explorative and friendly.
When real or perceived threat enters the scene, and threat challenges us,
the ventral vagal "brakes" the mobilization process and we experience DORSAL vagal activity, such as mild to moderate to severe withdrawal, basically demobilizing states.
When real or perceived threat is experienced as insurmountable,
we shut down even more and emotionally remove ourselves from the scene
as observed in the "freezing response",
simulation of death and complete immobilization
NOTE THE FOLLOWING:
Stimulation of the ventral vagal releases an array of anti-stress enzymes and hormones such as acetylcholine, prolactin, vasopressin, and oxytocin. Acetylcholine assists digestion and has an inhibitory effect in cardiac tissue, lowering heart rate and blood pressure.
Deep Rhytmic Breathing, with a long and slow exhale, is key to activating your ventral vagal branch, slowing heart rate, lowering blood pressure, especially when stressed and times of challenging performance anxiety.
NOW FOR THE REST OF THE STORY:
Lets see what happens when the newest vagal branch (ventral vagal) interacts with the sympathetic division and the dorsal vagal.
The ventral vagal is the most recent and the vagal dorsal is the oldest and most primitive in terms of evolutionary development. The ventral vagal lowers mobilization, as does the dorsal vagal, both applying brakes to sympathetic mobilization observed in heightened emotional arousal.
Important emotional states surface when ventral vagal and dorsal branches interact with each other AND when one or the other interacts with the sympathetic subdivision of the ANS.
The first surfaces when the ventral vagal interacts with the sympathetic subdivision, which generates mobilization "without fear" as experienced in all forms of relaxed movement. We observe this in friendly, playful activities such as when dancing, when we are joyfully engaged in various sports, both competitive and non-competitive. During these activities we are indeed active, we do flow, we can be socially engaged, and we can act alone or in groups, such as during dance, Yoga, Tai Chi and playing a musical instrument. We are social animals but we also spend time alone. Both experiences are fulfilling when we are relaxed, balanced, flexible and focused, performing well, In The Zone.
The other surfaces when the ventral vagal interacts with the dorsal vagal, generating immobilization "without fear" as we move toward inner calm, personal safety and interpersonal trust. We are socially engaged, quieter physically, feeling safe and secure. During these times, we can be intimate and loving. A genuine hug provides a good example.
HOWEVER, when real or perceived threat becomes overwhelming we shut down, proceed toward interpersonal isolation, we back away from threat, may display the freezing response. We will dive even deeper into isolation as threat increases, We can become fully shutdown, feign death and ultimately exhibit complete immobilization.
This theoretical view of the ANS is brought to us
the innovative, scientific work of
Dr. Stephen Porges and his Polyvagal Theory