Nervous System Regulation: Part Two
The work I do as a Holistic Health Practitioner is grounded in Mind Body Medicine, which is all about the connection between our thoughts, emotions, feelings and physical wellbeing.
I can talk about this connection in an intuitive way, and most people recognise that yes, we are 'one being’, and that our mind and body are connected and have some kind of influence on one another. However, understanding the actual mechanisms of how this occurs can demystify mind body medicine and transform it from something that sounds a bit pseudo-spiritual-wellness by understanding the science behind it.
In this article we are going to explore the role that the nervous system plays in Mind Body Medicine, what stress is and how it affects nervous system function.
The nervous system acts like an interface between our thoughts (mind), feelings, emotions and our body. As mentioned in the first article in this series, the nerves of the Peripheral Nervous System are the two-way communication pathways between our brain and other parts of our body. This communication is more like a conversation, because it flows in both directions. These are the pathways that allow our mind and body to communicate as one.
The Peripheral Nervous System carries information from our brain to our body (e.g. the brain telling our muscles to work so that we can move) and from our body to our brain (e.g. sensory input like heat or sound).
So, how do they actually talk to each other?
The Nervous System is mainly made up of cells called neurons. Bundles of neurons are called nerves. Nerves are responsible for carrying messages to and from the brain and to different parts of the body. Neurons are connected to each other, and to other cells, by synapses, which carry electrical signals, and neurotransmitters, which are the body's chemical messengers. Examples of neurotransmitters include dopamine, serotonin, histamines and noradrenaline.
What is Stress?
Stress is our reaction to a condition - a threat, an experience, a challenge, an event, a psychological barrier or physical event (illness or injury).
Stress is a non-specific response, what varies is the degree of response an individual experiences and to what condition (or perceived condition).
What this means is that stress is a very personal experience that starts with perception. What one person finds stressful might not be stressful for someone else. The experience of stress comes down to how we perceive certain experiences. This is influenced by our expectations, beliefs, culture, social programming, personality, life experiences, our existing health conditions.....the list goes on.
It is important to understand that stress is nuanced and individual. We can't presume to understand another person's experience based on what we personally consider 'stressful' or not.
In saying that, there are certain situations that are commonly experienced as stressful, such as;
The death of a loved one
A traumatic event (e.g. war, violence etc)
Abusive relationship
Overly demanding jobs
Financial worries or losing a job
Relationship breakups
Being really busy and managing expectations and deadlines
Illness, injury or disability
Caring for a loved one with illness, injury or disability
Inadequate sleep
Poor nutrition
Oppression, racism, discrimination
Not all stress relates to large life events or external situations. Stress can also come from internal expectations, fears, insecurities, feelings of low self worth, shame, or not prioritising and meeting our own needs.
Not all stress is created equal. It's a bit of a myth that 'all stress is bad'. Small amounts of stress can be good for us. Hermetic Stress is a type of stress that is acute and short-term. This type of stress can have health benefits and help us build resilience, for example being exposed to cold (e.g. a cold shower or a short swim in cold water) or high-intensity interval training.
The kind of stress that dysregulates our nervous system is chronic stress and acute stress where we experience 'distress'. Stressors are more likely to affect our health when they are "chronic, highly disruptive, or perceived as uncontrollable."
How Does Stress Affect The Nervous System?
The number one effect that stress has on the nervous system is the activation of the Sympathetic Nervous System (SNS). The SNS is linked to our ‘fight, flight, fawn and freeze’ responses. These survival responses are wired into our system to help us stay safe when we perceive a threat.
When the SNS is activated this triggers a number of responses cognitively, emotionally and physically.
Earlier in this article neurotransmitters were mentioned. They are the chemical messengers that deliver information back and forth between the body and the mind through the nerves of the peripheral nervous system.
When the SNS is activated by our reaction to stress, that triggers a cascade of hormones and neurotransmitters to release throughout the brain, affecting thoughts, decision making processes and behaviour. The neural circuits involved in emotion and brain function are inextricably linked, and this delicate neurochemical balance can be easily disrupted by exposure to stress.
Chronic stress increases glucocorticoids, which create cellular changes in the hippocampus. Over time this impacts cognitive ability, reducing attention and focus, perception, short term memory, learning and ability to find the right words (recall) when speaking.
Activation of the SNS releases two hormones within the body in response to stress, resulting in a sense of urgency that occurs during stressful conditions. These hormones are called epinephrine and norepinephrine
The adrenal glands release the epinephrine (adrenaline) and cortisol, which stimulate a number of further systems to prepare the body to respond to the stress or threat:
Widening of the airways via bronchioles in the lungs to increase oxygen supply to the blood and the rest of the body
Increased heart rate delivers oxygen and nutrients to the brain and the muscles to prepare them for the stress
An increase in glucose, released from the liver into the bloodstream to provide more energy to the muscles
Slowing down of digestive activity, which helps conserve your body's energy that can be used to defend itself against stress
These physiological responses to stress are designed to keep us safe, however when they happen chronically (consistently over an extended period of time) our overall health can be impacted. This is why regulating our nervous system, and creating a sense of safety, relaxation and rest can be so healing for our mental, emotional and physical wellbeing.
In the next article we will cover how you can identify that your nervous system is dysregulated, how that may feel, and what behaviours and interactions could be impacted.
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