I want to start by saying that the nervous system is MASSIVE and complex. So, what you will read in this short mind splat is truly an overview and not in the least bit detailed. However, every day is a learning day, so I hope there is a nugget of new for you.
In the beginning there was the central nervous system and the peripheral nervous system. The central nervous system involved the decision-making part of things (which include the spinal cord and brain). The peripheral nervous system involves the information transport part of things (which involves all the other nerves not included in the central nervous system). Our nervous system detects, transports, interprets and responds.
Then there was the somatic nervous system which controls voluntary movement (do a squat) and the autonomic nervous system which controls involuntary movement (digest that avo). So much of what we do is unconscious!
Under the umbrella of the autonomic system are the sympathetic and parasympathetic nerve supply. The sympathetic nervous system is the ‘stress response’; it supplies all internal organs. So, for example, blood pressure will increase, and the skin will secrete sweat. The parasympathetic is responsible for slowing and balancing the body systems. The parasympathetic consist of mainly vagus nerves. The parasympathetic nervous system is what we bring in to play when we breathe slowly, meditate and be mindful. We need more of this and less of the stress response.
The central nervous system (brain and spinal cord) contains many a control centre. The left side (logic, language and numbers) controls the right side of the body. The right side (creativity), you guessed it, controls the left side of the body. Some people dispute this. The cerebellum controls movement. The hypothalamus controls hormone release and the autonomic nervous system. The hypothalamus is the part that can speak via nerves or hormones and so is the main link between the endocrine and nervous system. A truly magical part of the brain, for sure. The thalamus is part of the limbic system which is involved in sensory perception and regulation of motor functions. The brain stem joins the brain to the spinal cord. Grey matter is where processing takes place. White matter is involved in communication and regulation of many things, including emotion and temperature. There is so much more going on under your hood!
The peripheral nervous system comprises of cranial nerves, vagus nerves and spinal nerves. The cranial nerves supply the muscles and sensory organs of the head and neck. The vagus nerves are part of the parasympathetic nervous system and controls the stomach, intestines, lungs, heart, kidneys and much more. The spinal nerves are named after the vertebrae that they are connected to e.g. lumbar nerves.
I’ve been going on about nerves, so, here’s the basics. A nerve (which can be up to 1metre long) is made up of lots of neurons (or nerve cells). A signal will be passed electrically within the neuron but then it is passed chemically when the signal moves across to another neuron (through a synapse). Nerves can be damaged by a lack of oxygen and, mostly, they cannot be replaced when they die. Recovery from nerve damage is variable. Receptor cells detect energy changes in the environment and turn them into electrical impulses, could this be the explanation for sensing reiki? Afferent neurons take information from an organ, whereas efferent neurons send information to the organ.
Now, for some fun facts:
- The stimulation of the nerve receptors in massage can result in the endocrine system releasing its good guys (happy hormones).
- Nerve impulses can travel at a speed of 100 meters per second – THAT’S FAST.
- Essential oils properties contain properties that are said to influence the nervous system e.g. nervine relaxant oils.
- The sciatic nerve (goes from lower back, through the hips and down each leg) is the thickest nerve at approx. 2cm!
- Reflex actions that need to happen quick, such as taking your finger out of that boiling melted camembert, are decided in the spinal cord!
- The vagus nerve consists mainly of afferent (from organ to brain) neurons. Imagine how much information is being passed to the brain if only 20% of the nerve is efferent (from the brain to the body).
- The vagus nerve is said to influence breathing, digestion, microbiome, inflammation and immune activation, heart rate, stress, sleep and sociality (apparently more than this from other sources).
- Pain modulation and then pain perception are factors in the transmission of pain signals through the nervous system to the brain. This can help explain why we have different responses to pain or have different pain thresholds. Pain sensitisation is also something that can occur when nerve cells are over stimulated.
- Up to one third of people seen in an average neurology clinic have neurological symptoms that cannot be explained. The two most common psychosomatic illnesses are fatigue and pain. Interesting!
- Our brain signals can cause physical responses to emotions. For example, you cry when you are happy or sad (salty water, random right?), the child gets a stomach cramp when he is being bullied at school and the blushing that occurs when you see your crush. It’s not as simple as a ‘to and fro’ of information, emotions get involved.
- Mindfulness is being researched in its ability to help with the experience of pain, the smaller studies are there, however more and larger randomised control trials are needed. Cognitive behaviour therapy is a talking therapy which is frequently used at present. Reconsider your sources of healing.
Next time you meditate, observe if there is a parasympathetic response.
If you need help, reach out, I have lots of resources.
I hope I have tickled the cells in your grey matter. I hope there has been a nugget of new.
For a further nuggets, please see my book suggestions below.
For a book about neurosurgery, my suggestion is ‘Do No Harm’ by Henry Marsh – fascinating and not a dry read.
For a book about psychosomatic illness, my suggestion is ‘It’s All In Your Head’ by Suzanne O’Sullivan – highlight the complex nature of our brain and also fascinating.
For a book about all of the body, my suggestion is ‘Adventures In Human Being’ by Gavin Francis – an easy to read overview.
References:
Anatomy and Physiology Revision
Habib, N. (2019) Active Your Vagus Nerve: Unleash your body’s natural ability to heal. Ulysses Press: Berkeley
Marsh, H. (2014) Do No Harm. Phoenix: London.
Melzack, R. (1973) The Puzzle of Pain
Francis, G. (2015) Adventures in Human Being. Profile Books: London.
O’Sullivan, S. (2015) It’s All In Your Head. Vintage: London