A Look into the Nervous System Part 1: Fight or Flight

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Written by Dr. Georgia Tetlow MD and Clare Abercrombie, BS

Many of our readers have heard of the “flight or fight” response, but what controls this response, and why should we care? Our next two posts will explore the two sides of our autonomic nervous system and how these systems affect our daily lives. The autonomic nervous system is composed of the sympathetic and parasympathetic nervous systems, and only one is predominant at a time. As humans we are hardwired to have two channels, but only one expresses itself at any one time. Either the sympathetic or parasympathetic system controls expression of our hormones, neurotransmitters, reactions, brain and organ functionality, to name a few.  At Philadelphia Integrative Medicine, we look at each patient holistically, with the goal of understanding the root cause of conditions. This exploration into health and wellbeing includes a look into which aspects of the autonomic nervous system are predominant, and how the central nervous system may be affecting chronic illness/es and current symptoms.

A Note on Humans’ Hard Wiring

Our brain sends action potentials down our spinal cord to what is called a “ganglion”. Think of ganglions as a stopping point for neurons before they continue their path to their final destination. Since we have two nervous systems, the sympathetic and parasympathetic, what happens after this stopping point will be very different, depending on nervous system state we are in. At the ganglion, the neuron synapses to a connecting nerve, and then connects to the  “effector organs” (the final destination) where neurotransmitters, hormones, or both are released. Which neurotransmitters or hormones are released are dependent on the initial signals sent out from our brain--signals of fear or safety, representing sympathetic or parasympathetic states.

What is the Sympathetic Nervous System?

The short answer is that the Sympathetic Nervous System is the the body’s physical expression and experience of being afraid--being in a state of fear, paralysis and/or self defense. Let’s explore an example. Your smoke alarm goes off and your first instinct is to run out of the building. Upon hearing the alarm, your brain sends messages down your spinal cord to your organs to assist you in running from the danger. Which organs are affected? Neurons travel to your heart and your leg muscles to allow your body to focus on running from the danger. This system is the Sympathetic Nervous System (SNS), the physiology of stress, self preservation and fear. All your organs are connected to this system, experiencing input from either the SNS, or the parasympathetic nervous system (PNS). You can never have both systems activated at the same time, one reason you don’t run when you are asleep!

How does the Sympathetic Nervous System Affect our Daily Lives?

The physiology of stress does not differentiate between a life threatening situation and a stressful situation. This means that when you experience stress even in a small way, your SNS is active and your PNS inactive. Why does this matter? If you experience problems with digestion, high blood sugar, chronic dry mouth or eyes, or high blood pressure, all these health conditions can be caused by chronic SNS activation. When you experience ongoing stress and are unable to turn off the SNS switch, you are more likely to experience symptoms of a chronic fight and flight, or emergency state. Of course there can be other reasons for the symptoms listed, we don’t want to oversimplify.

Integrative Medicine helps you Find a Balance

It is important to create a balance between our two nervous systems--the sympathetic and parasympathetic--these two different expression of our mind-body state! Our bodies evolved to have these two separate systems (or states, or modes) for good reason--while the SNS allows us to run from danger and protect us when in harm’s way, the PNS is the system that allows us to relax, laugh, love, and create. If the SNS is constantly activated due to stress or anxiety, PNS effector organs like those in your gastrointestinal tract will malfunction. Integrative medicine treats through a “whole systems approach”. We often explore the connection between physiological health with mental wellbeing. Practices that activate the PNS (and “switch-off” the SNS), and that encourage a natural internal self-regulation include mindfulness and other forms of meditation, relaxation techniques, movement arts, biofeedback, and many others.

If you are stressed, don’t forget to laugh, love, and be mindful--and to invest effort in a mind body practice that sheds light on your personal stress triggers--some of these represent “real” dangers, and others arise from our past conditioning and emotional hardships. Is stress inside us or outside us? How can we authentically spend more time in a parasympathetic (resting/healing) state? Our next post will explore the ins and outs of the parasympathetic nervous system and how we can live there more often!

PIM wants to hear from you! Do you have an experience with managing your stress response? Did you find this article helpful? Leave your thoughts in the comments below!

Interested in connecting with PIM? Register for one of our upcoming events - our next FREE Group Class at Cabrini College is 3/14 Bad Bowels (please RSVP online) OR Nutrition Classes with our very own Rachel Hershberger, MS, CNS, LDN, tickets just $45 at sign up (limited to 8 participants for individual attention, no walkins, please).

If you or your loved one has ongoing stress, mood or hormone imbalance, or they are suffering from a chronic illness, please consider scheduling a 20 minute free consultation or an appointment with Lauren Houser, MS, MSN, CRNP or Annmarie McManus, MMSc, PA-C, PT, IFMCP.