So, here you are, in this human body, born into this world. And with it comes a mysterious consciousness from which you can read this blog post, from which you can think about and contemplate how your body functions.
It’s a trip, isn’t it? You don’t just have a brain, a spinal cord and a nervous system, you can also know that you have one. It puts us into an interesting dilemma. One in which we’re not simply afraid in each moment, but we can remember fearful events from the past, and be afraid of the future.
I’m going to tell you how the nervous system works. I’m doing this as part of a series on anxiety. So if you’ve stumbled on this post by itself you may want to stop here and go read my Resigning from Anxiety post, where I tell my story about being a paramedic, about getting anxiety after a man died in my ambulance, and what I did to heal. You can also check out my next post, What the Human body does with Stress: and how to fix it. (it’ll be up next week).
Ok science buff’s… Let’s get into it…
The Nervous System
You have a brain, a spinal cord and a whole bunch of nerve cells. Some of them are super loooooong, some of them are short. Some take signals from your five senses up your spinal cord to your brain, and some take signals from your brain to your body.
There are a few ways to divide the nervous system, but for the sake of this conversation we’re going to focus on two parts:
voluntary or somatic nervous system
involuntary or autonomic nervous system
The Somatic Nervous System
Voluntary means that you can command your body to do something. You decide that you want to move your hand, and the signal is sent and you do just that. Take a moment now to consciously command a part of your body to move.
Did you really do it? If not, stop reading and do it!
Miraculous isn’t it? This voluntary aspect of your nervous system is called the Somatic Nervous System.
The Autonomic Nervous System
Involuntary is the part of you that is constantly running in the background. It’s your heart beat, your metabolism, breathing, digestion, fertility. All the millions of things happening inside of you at any given moment that you don’t have to think about. Take a moment to contemplate something that is happening inside of you right now, your heartbeat for example.
Did you really do it??? Go on…
What a miracle right? This part of your system is called the autonomic nervous system.
Now, you have some voluntary control over the involuntary. For example, you can purposely slow your breath or maybe even your heart beat. You can hold your breath. But for the most part, these functions are happening without your control.
Spiritually speaking, I love to stop and ask my clients to consider this when I do a live event on the nervous system. That they can change, but not ultimately control their body. You did not get to choose to take your first breath, it was given to you.
Life began without your permission. It happened due to causes and conditions that had nothing to do with your individual consciousness. There are infinite causes and conditions that led to your brain, spinal cord and nervous system being in existence: the sperm and egg of your parents: the process of cell division and replication and every process that happened before your parent’s parents. They were all out of your voluntary control.
Likewise, you will not get to decide which breath will be your last.
Take that in.
It’s pretty awesome that we get to feel like we have some control in this life that is actually uncontrollable. It’s the somatic nervous system that lets us do this. We will go over how you can voluntarily affect your involuntary system later to reverse the symptoms of stress. But for now, we really need to talk about the autonomic nervous system, as this is where the stress response happens.
You still with me?
The two parts of the Autonomic Nervous System
+Sympathetic Nervous System
+Parasympathetic Nervous System
+Enteric Nervous System
Ok, so I lied, there are actually three. The enteric nervous system (ENS) is embedded in the lining of the gastrointestinal system and is sometimes referred to as “the second brain”. But we’re going to have to ignore it today as it’s not a key player in the stress cycle (also not entirely true). I can get pretty distracted when it comes to the amazing functions of our human body so I’m having to force myself to let it go. (And if you really want to have your mind blown, you can do your own research on the ENS later: its incredible!)
Back on track: you may have heard of the Sympathetic NS as “flight or flight”, and the parasympathetic NS as “feed and breed”. Those terms are pretty explanatory but not the whole story. The two systems can work together, though its often easier to consider them as opposites. In a spiritual and energetic sense, you can relate to them to yin and yang. Yin is cold, dark, slow, and restful. Yang is fire, light, fast and doing.
Sympathetic Nervous System (SNS)
The SNS is often thought about in a dramatic way. Fight or flight conjures up pictures of cave men running from lions or an axe murderer chasing a screaming woman down a street. But another way you can look at the SNS which covers all bases, is that it is responsible for physical and mental activity.
Any time you’re doing, trying, or being you are using some level of SNS. This may include sitting on the lounge watching TV, if the show you are watching is quite action filled. Ever been reading a scary book and had your heart thumping? Ever had a nightmare and woken up sweating and afraid? My point is, you can be lying or sitting quite still and have an activated SNS. This becomes important later when we talk about stress.
What Happens when the SNS is activated
When a threat, or stressor occurs, the amygdala (the part of the brain that processes emotion) sends a signal to the hypothalamus.
The hypothalamus (the part of the brain that controls and commands your Autonomic NS) activates the Sympathetic NS by secreting two chemicals, epinephrine and norepinephrine (known in Australia as adrenaline and noradrenaline).
These chemicals have the following rapid effects on the human body:
Increases Heart Rate and force of contraction
Constricts blood vessels, which leads to
Increased blood pressure
Dilates pupils (to let more light in for sharper vision)
Contracts voluntary muscles (body becomes physically tense, ready for action)
Quickens breath (getting ready to do/run/fight/perform)
Narrows mental focus (becomes more difficult to see a wide view or make decisions not related to the stress inducing event)
Rapid increase in blood sugar
Shuts off gastric mobility
The production of these chemicals, and the changes they cause, occur so immediately that your conscious mind may not even be aware. This is how we see people react to a danger without even thinking… ie swerving in a car accident or jumping out of the way of a threat.
Once the initial adrenaline wears off, a complex system is in play to release more hormones that keep the body activated over longer periods of time if the threat or stressor still exists, called the HPA axis. The HPA axis is more complicated than I wish to get into in this post so if you want more you can read this excellent article by Harvard Health.
In short, the HPA axis causes the body to continue the initial changes at a slightly decreased rate, while also releasing cortisol, elevating blood sugar, decreasing immune function, and shutting off non-necessary functions such as renewal, repair and general healing.
The long term effects
You could see, then, that there are obvious problems that would arise in the human body if one was to remain in a state of stress. Chronic high blood pressure, high blood sugar, contracted muscles, shortened breath, decreased gastric function and immunity, and an inability to heal and repair.
Doesn’t sound great does it?
A complication of humanity is that we do not simply experience physical stressors: we experience psychological stressors too. Rejection, isolation, money stress, relationship stress. All of which activate the SNS as easily as a hungry lion showing up at our cave door.
We are experiencing SNS not just in our physical reality, but in our mind too.
The Parasympathetic Nervous System
The PNS is known as Feed and Breed, and is responsible for all that occurs when the body is at rest, including sexual arousal, salivation, lacrimation (tears), urination, digestion, and defecation. It slows the heart rate and relaxes the muscles, dilating blood vessels and thereby lowering blood pressure. The PNS is also known and Rest and Digest, and is activated when the body is doing just that. During this time, the body can restore, repair, and heal.
Stress Response vs Relaxation Response.
Another way to relate to these two parts of our ANS is to describe the SNS as the stress response and the PNS as the relaxation response.
Looking at it this way, we can then investigate our overall system for balance. How often are you activating your stress response? And how often are you activating your relaxation response?
Not all stress is bad. We need to have some SNS stimulation for our physical and mental activity, but we can get stuck in a negative stress cycle, leading to chronic stress, physical tension and anxiety.
Likewise, being in a relaxation response all the time wouldn’t be smart. Nothing would get done and we would all be like the humans in the movie Wall-E, lying around like big blobs with push button remotes. This may lead to lethargy, decreased joy and possibly even depression. Many studies have linked too much sleep to depression.
What matters is balance. When speaking to my clients about anxiety I usually assume that they are out of balance with too much SNS stimulation. I assume that they are stressed, so I teach ways to activate the relaxation response. There are may ways to do this…
Activating the Relaxation Response
Below is a list of ways I have learned to activate my relaxation response
Deep breathing or abdominal breathing
Relaxation guided meditations
Yin Yoga, or slow flow
Mindfulness, both in formal settings and in walks or tasks
Time in nature
Listening to beautiful music or sound healing
Journalling, dream writing or dream drawing.
It is important to remember that reading a book or watching tv usually will not stimulate the relaxation response because your mind is engaged in activity. Similarly, meditation that is filled with worrisome thoughts may not do the trick. For the reversal of stress and anxiety symptoms, emphasis is on guided meditations which encourage grounding, presence and relaxation.
Stay Tuned
While I am mostly anxiety free now, my body is very sensitive. Because of this I am careful to remove stimulants to my SNS. I make wise choices about the music I listen to, the TV I watch and the people I choose to interact with. I keep my environment relaxing and peaceful. And these days, I’m sad to say it, I limit my intake of alcohol and coffee.
I still want to be lighthearted and live my life, so to me, there’s no such thing as a hard no. But I bring mindful attention to what I ingest through my senses to keep my body at peace. Also, I remind myself often that I am safe. To take a long deep breath and drink in beauty around me.
I hope that this post has helped you to understand that stress is a natural response of the human body. That tension and anxiety are simply increased levels of chronic stress that haven’t been tended to.
If you haven’t already, read the full story of how I resigned from anxiety.
You might also want to check out What a human Does with Stress and how to fix it: there’s a great exercise in there for you to do.
And if you’re really serious about chilling out, take the FREE 5-Day Chill Out Challenge
Or join Heal & Reset the online course.
Sources Lumen learning & Harvard Health
