The nervous system
The network that allows us to function
You probably heard the expression countless times: the “nervous system”. You might have an idea, you might know the anatomy, but this post will clarify and explain what exactly the nervous system is, what are its functions and how does it work.ย
The human NS is a marvel of complexity, orchestrating the symphony of our thoughts, actions, and perceptions. At the heart of this intricate network lies the brain and spinal cord, working in tandem to regulate our body’s functions and enable us to experience the world around us. In this blog post, we will delve into the fascinating world of the NS, starting with an exploration of the brain’s different parts and functions, and subsequently, understanding the significance of the spinal cord.
The Brain: command center
The brain, weighing just about three pounds, is a powerhouse of activity that governs our every move and sensation. Comprising numerous specialized regions, each with unique roles, the brain collaboratively ensures our survival, emotions, and cognition.
Some terminology:
Cerebrum. It is theย largest part of the brain, the cerebrum, is responsible for higher-order functions like conscious thought, reasoning, sensory perception, and voluntary muscle movement. Divided into two hemispheresโleft and rightโit further segregates into four lobes: the frontal, parietal, temporal, and occipital lobes, each contributing to different aspects of our experience.
Cerebellum.ย Nestled beneath the cerebrum, the cerebellum is tasked with coordinating movement, balance, and posture. It plays a crucial role in ensuring fluid and coordinated physical activities.
Brainstem. The brainstem connects the brain to the spinal cord and controls fundamental bodily functions such as breathing, heartbeat, blood pressure, and digestion. It’s comprised of the midbrain, pons, and medulla oblongata.
Limbic System. This intricate system governs emotions, memory, and motivation. The hippocampus processes memories, the amygdala manages emotional responses, and the hypothalamus regulates bodily functions and hormone production.
The Spinal Cord: Information Superhighway
Running from the base of the brain down the spine, the spinal cord acts as a vital conduit, transmitting sensory and motor signals between the brain and the rest of the body. Its structure comprises a central gray matter region surrounded by white matter columns.
Sensory pathways: The spinal cord plays a pivotal role in relaying sensory informationโtouch, pain, temperature, etc.โfrom different parts of the body to the brain for processing and interpretation.
Motor pathways. Conversely, motor signals generated in the brain are transmitted through the spinal cord to muscles and glands, orchestrating movements and physiological responses.
Reflex arcs. The spinal cord also hosts reflex arcs, allowing rapid, involuntary responses to potentially harmful stimuli. Reflexes occur without conscious thought, showcasing the spinal cord’s ability to process information independently of the brain.
Somatic and autonomic
Somatic
The somatic nervous system is responsible for the voluntary control of our body’s movements and the conscious perception of sensory information. It consists of sensory and motor neurons that transmit signals between the central NS – or CNS – (brain and spinal cord) and the muscles, skin, and sense organs. Here are the key points:
The somatic NS is under our conscious control. When you decide to move your arm, walk, or scratch your nose, you are consciously using this system to initiate and control those movements.
It processes sensory information from the external environment and sends it to the brain for perception. This includes sensations like touch, pain, temperature, and proprioception (awareness of body position).
The somatic NS controls skeletal muscles and is responsible for executing voluntary movements. It sends signals from the brain to the muscles to carry out specific actions.
The pathway in the somatic nervous system involves a single neuron, called the upper motor neuron, which originates in the motor cortex of the brain and directly connects to the skeletal muscles.
Autonomic
The autonomic nervous system, on the other hand, is responsible for the involuntary regulation of internal organs and bodily functions to maintain homeostasis, the body’s stable internal environment. It operates without conscious control and is divided into two main branches: the sympathetic nervous system and the parasympathetic nervous system. Here’s a breakdown:
The autonomic nervous system operates involuntarily and automatically. It controls functions such as heart rate, digestion, respiratory rate, and blood pressure without us consciously thinking about them.
It regulates the internal organs, glands, and smooth muscles of the body. This includes controlling processes like digestion, circulation, respiratory rate, and glandular secretion.
The autonomic system is divided into two branches that often have opposing effects to maintain balance. The sympathetic nervous system is associated with the “fight or flight” response, preparing the body for intense physical activity. The parasympathetic nervous system is associated with the “rest and digest” response, promoting relaxation and conservation of energy.
The pathway in the autonomic nervous system typically involves two neurons: the preganglionic neuron (originating in the central nervous system) and the postganglionic neuron (extending from the autonomic ganglion to the target organ).
In essence, the somatic nervous system controls voluntary movements and conscious sensory perception, while the autonomic nervous system regulates involuntary functions and maintains internal balance. Both systems work together to ensure our body functions optimally in response to internal and external stimuli.
Sympathetic and parasympathetic
The parasympathetic and sympathetic nervous systems are two distinct branches of the autonomic nervous system with opposing functions that work together to regulate various bodily functions. Let’s delve into the differences between the parasympathetic and sympathetic nervous systems:
Parasympathetic NS:
“Rest and Digest”
The parasympathetic nervous system is often associated with promoting a state of relaxation, recovery, and energy conservation. It dominates during times of rest and recovery when the body is not facing immediate threats.
Functions
It is responsible for slowing down heart rate, constricting the pupils, stimulating digestion, and promoting bodily processes that occur when the body is at rest. This includes activities like salivation, digestion, and elimination.
Neurotransmitter.
The primary neurotransmitter used by the parasympathetic nervous system is acetylcholine. It is released by both the preganglionic and postganglionic neurons, transmitting signals between nerve cells.
Location of ganglia
The preganglionic neurons of the parasympathetic nervous system are located near or within the target organs, and the postganglionic neurons are short, making them close to the target tissues.
Craniosacral Outflow
The parasympathetic nervous system is often referred to as the craniosacral outflow because its preganglionic neurons originate in the brainstem (cranial nerves) and the sacral region of the spinal cord.
Sympathetic Nervous System:
“Fight or Flight” Response
ย The sympathetic nervous system is known for triggering the body’s rapid response to stress or threats, preparing it for intense physical activity or a “fight or flight” situation.
Functions
ย It increases heart rate, dilates pupils, redirects blood flow away from the digestive system towards skeletal muscles, stimulates the release of adrenaline, and initiates processes that boost the body’s ability to respond to emergencies.
Neurotransmitter
The preganglionic neurons of the sympathetic nervous system release acetylcholine, but the postganglionic neurons release norepinephrine (also known as noradrenaline), which activates the fight or flight response.
Location of Ganglia
ย The ganglia (clusters of nerve cell bodies) of the sympathetic nervous system are located closer to the spinal cord, along a chain extending parallel to the spinal column.
Thoracolumbar Outflow
The sympathetic nervous system is also referred to as the thoracolumbar outflow because its preganglionic neurons originate in the thoracic and lumbar regions of the spinal cord.
In summary, the parasympathetic and sympathetic nervous systems are complementary branches of the autonomic nervous system that balance each other to regulate various bodily functions. The parasympathetic system promotes relaxation and digestion, while the sympathetic system prepares the body for action and heightened alertness. Together, they help the body respond appropriately to different situations and maintain internal equilibrium.
Edoardo Elisei DC
Alive Chiropractic LTD
alivechiropractic.co.uk
1C Crown Gate Square
POUNDBURY
01305602314
15/8/2023
I have 38 years of patchy recovery from a nursing back injury.
This intensive approach has markedly reduced my painful episodes and spinal posture problems.
My family has noticed a big difference in me with many obvious and subtle improvements.
I look forward to continuing this progress with both Edo and Phil to achieve further improvements.
Saved me from different injuries and helped me a lot of chronic issues I was dealing with.
He is a saviour.
Highly recommended
You are always polite, very knowledgeable with great approach to patients.
To all interested - do not hesitate, I highly recommend! See you soon!
Will definitely be visiting again!
I would fully recommend Alive Chiropractic,
Edo is a very warm, welcoming caring and does not judge.
He explained what and how he was going to help me , had an extensive treatment period to begin with and then became a monthly visitor .
He has been so much help to me over this time and I would recommend his gifts to everyone.
A truly lovely man and gifted communicator and practitioner.
If in pain go and give him a try , living in a body that feels like a prison is no fun but this guy has the keys to set you free!
Offers practical advice for individuals of any age
Explains proposed programs well
Very confident that treatment will be successful
Highly recommend
I am sleeping more comfortably again, my walking has improved too, my confidence has improved, I was treated with great respect. I have learnt new exercises which also has helped thanks to Ed owner of Alive chiropractor and Phil too for his excellent deep tissue massage therapy. I cannot thank them both enough, I feel like a new person!
Iโve now signed up for a regular maintenance programme. Thank you both very much, itโs very much appreciated.
He certainly has 'healing hands'.
Clearly passionate about his profession, not only does his treatment keep you supple. He also gives plenty of advise & exercises to keep yourself active.
The waiting room area is that of peace & tranquility with soothing background music.
There is ample free parking.
You've nothing to lose but everything to gain if you want to stay fit, healthy and active.
I highly recommend his expertise & personalised approach.
I highly recommend Edo and Alive Chiropractic. Great service from initial assessment, to treatment, and ongoing progress checks. As well as a range of exercises to continue at home.
As well as the work he done with me in the clinic, he has taught me many different exercises to help me with the problems in which i suffer with, as well as explaining to me how my diet can also help me going forward.
He has been a great help, and i shall continue to see him in the future so that he can help me maintain ( and improve) my well being.
Regards
Peter
Dr Edo provides a whole body approach to resolving chiropractic issues. His care plan to help solve your unique issues is fantastic, short and simple adjustments rather than long sessions of big adjustments has worked brilliantly for me. Communications are easy and booking ahead is brilliant for me and my schedule.
I canโt recommend Alive highly enough!
The reception is also very welcoming. I very much recommend this place!
Dr Edo is professional, knowledge, and believes firmly in his work which he is clearly passionate about. I feel he has an empowering vision, cares deeply, and has a refreshing balance of western and eastern understanding. Because of this, Dr Edo has a deeper, holistic approach by taking into account all aspects of one's lifestyle (diet, exercise, mental/emotional state) in sessions. For someone like myself who values a holistic perspective on health, Dr Edo's approach is invaluable and helped me relax and feel at great ease. Sam in reception is lovely and you instantly feel welcomed when coming in for a session also. Thank you to you both. Highly recommend!
Thank you!
I will happily recommend Alive Chiropractic to my friends.
Ed takes a very holistic approach, encouraging me to lose weight and work on different rehab exercises to reinforce the manipulations and adjustments he made.
Here I am some three months on, I weigh a lot less, I have incredible flexibility in my lower back and can now touch my toes and, best of all. I have full flexibility of my neck.
Eds holistic approach really works, he is very approachable and easy to chat about things with.
One caveat, Ed knows when you haven't done your exercises so don't cheat. ๐
I cannot thank him enough for the massive improvements in my health and his encouraging me to make little changes for a healthier long term lifestyle.
