Basic Training Series: Nervous System Principle #8: CHEMICAL MESSAGE CODING

OKAAAAYYYY...

Here's the last one according to Angevine. Before I get into it, I want to say thanks to those who have been reading these posts. It's been a tremendous education for me to learn these principles. Now that I have them under my belt, so to speak, I will get more detailed with form and function.


"Chemical Message Coding
The basic function of the nervous system, from which all others derive, is communication, performed (with unsung neuroglial support) by neurons. It depends on special electrical, structural,and chemical properties of these diversified cells with their long processes, on their exploitation and refinement of two basic protoplasmic properties, irritability and conductivity, on their external and internal neuronal morphology featuring multipolar shape and integrative design, almost infinite modes of dendritic and axonal branching, widespread, diversified connections, and specialized organelles, and on their use of chemical substances to encode, deliver and decipher messages of their own and other neurons.

Neural circuits are chemically coded. Neuroanatomy encompasses interneuronal connections and also chemical mediators and transmitters. Neuroactive substances comprise neurotransmitters, neuromodulators, and neurohormones. Their definition in contexts other than site of action, postsynaptic neuronal activity, and corelease of one or more additional neuroactive substances can be misleading. Neurotransmitters are small molecules acting swiftly, locally, and briefly on target cells. Neuromodulators are very small (peptides), regulating but not effecting transmission, and neurohormones are also small, with intrinsic activity mediated by neuronal and other cells, exerting slow, widespread, and enduring influence via the extracellular fluid or bloodstream.

Neurons releasing hormones are quasi-endocrine cells, liberating secretory products from axonal endings into the perivascular space to be conveyed to blood vessels and thence to target organs. The provincial concerns of neurophysiology and endocrinology have fused into neuroendocrinology, as psychoneuroimmunology has united psychobiology, molecular neurobiology, and immunology."

Last one but so important as it deals with how the Neuromatrix sends signals all over the body. 

1) I love that Angevine says that "The basic function of the nervous system, from which all others derive is COMMUNICATION (with unsung neuroglial support) by neurons." 

2) These neuromodulators, neurohormones and neurotransmitters are essential to every function in the body. From all my research we are JUST starting to understand how powerful and influential these are. Of course pharmacology has been dealing with them for a while but the extent to which all of the above neurochemicals are affected is not fully known. 

For a GREAT book that is easy to understand, see Robert Sapolsky's "Why Zebras don't get ulcers". This book talks about Prof. Sapolskys favorite topic "glucocorticoids."

Honestly, this topic can is become complicated quickly, so I'm going to leave it at that. I look forward to learning more about them as it's important to trainers and therapists to understand that while we cannot directly affect the chemical coding, the process can be affected by something as simple as proper nutrition. 

Well, that's all for the Principles of the Nervous System.


Again, thanks for reading, and if you have questions or comments, please do not hesitate to post them.

In mind, body and spirit,

Will

Basic Training Series: Nervous System Principle #7: PLASTICITY

Okay, here's Principle #7, according to Jay Angevine:

"Plasticity
Highly reliable in a healthy person, the human nervous system has inherent modifiability, though in adulthood this attribute cannot approach that in invertebrates (moths and snails) or certain other vertebrates (teleosts and amphibians). In mammalian development, neural plasticity is striking. In continues postnatally. Abnormal visual experience at certain sensitive periods profoundly affects ocular dominance and orientation columns in the visual cortex. If an eye is closed at birth, ocular dominance columns for the other eye enlarge at the expense of adjacent blind eye columns, with thalamic fibers arriving in the cortex expanding terminal fields into them. If, shortly after birth, visual stimuli are restricted for a few weeks or even days to stripes of one orientation, cortical cells develop a response preference to lines of that orientation.

In humans, PET imaging studies of cortical blood flow show that tasks requiring tactile discrimination activate visual cortex in people blind at birth or having lost sight in childhood. This suggests that cortical connections reorganize after blindness: that afferent fibers to nearby cortical areas serving polymodal sensory integration usurp the bereft visual cortex. Such plasticity may explain the well-known tactile acuity of the blind.

In later development, neural plasticity operates on many levels, as in fine-tuning circuits to changing body dimensions. Depth perception is recalibrated as the skull enlarges and interpupillary distance increases. Even in adulthood, plasticity persists. Vilayanur Ramachandran has shown that a stroke with a cottonswab on the cheek of a young man who had accidentally lost his left arm led him to feel touch on his missing left hand. Later, the whole hand could be mapped on his face. The findings suggest that the deprived somatosensory cortical region for the hand becomes innervated by fibers from the adjacent face areas and that secondary input to a cortical neuron's broad receptive field becomes functional when primary input is lost.

After injury to the CNS, intact neurons form new terminals, by axon sprouting, to replace those of other neurons lost to trauma and thus reoccupy vacated synapses. Such reactive synaptogenesis, the clinically proven effectiveness of long-range regrowth of PNS axons, and the evident potential for axon regeneration in the CNS (as in teleosts and amphibia) hold promise for circuit reestablishment. But in mammals, these factors are thwarted by myelin debris, glial scarring, usurpation of sprouts, unresponsive injured neurons, and complex central connections. Developmental neuroscience now focuses on the cerebral cortex. The human nervous system appears to learn very rapidly by using preconstructed circuits and by locking neurons into specific types and functions after cell origin."

So this one is just AWESOME!  I was first introduced to this idea of "neuroplasticity" in the book The Brain that changes itself by Dr. Norman Doidge.  This book pretty much changed my life and the way I approached therapy and training/conditioning. I COULD go on and on, but I'll keep this one short too. Here goes my observations:

1) The first sentence mentioned in the HEALTHY person that the nervous system is able to be modified but no where close to invertebrates like moths and snails. However, it is still impressive. 

2) Dr. Angevine then goes into an example of how loss of sense like vision affects the brain. It seems the  neural resources that would have been utilized for vision are re-appropriated and still used. It seems the system has inherent intolerance for low usage of important structures and systems. 

3) A special interest to therapists and trainers, the nervous system changes based on dimensions of the body. Well, this is pretty intuitive. Something happens in the body (the skull was used by Angevine) and the nervous system recognizes this and adjusts so as to keep the body trekking on. Amazingly, all of this is under our "conscious" radar.  

4) When there is an injury to the body, like a loss of a limb, research has shown that plasticity starts remapping and the sensations of the lost limb can still be "felt." Ramanchandran demonstrated this when by touching the face of a patient who had lost a limb but the tactile sensation was still experienced. Whoa! 

5) In the final paragraph, Angevine discusses how the when the CNS is injured it can replace some of the structure in FROGS. Ugh... He explains that the other body processes that accompany the injury can thwart the regeneration; HOWEVER, there was some research done that stated:

"Wernig et al in Proc Natl Acad Sci U S A May (2008) have achieved a real breakthrough. They have been able to convert fibroblasts to neurons. These converted cells form into neurons, glia, and even dopaminergic cells. There has always been concern that converted cells might form tumors, but these scientists painstakingly separated the cells turned into neurons from pluripotential cells with fluorescent stains."

So, there's hope after all. Ordinary cells can be converted into neurons given the proper transcription factors. 

This principle is so important to me as a therapist, trainer and coach as we see that changes can occur not only in the body but in the all important nervous system. If our brains couldn't adjust all the REMARKABLE changes that took place in the mesodermal-derived structures like bones, joints, muscles, fascia, etc, we would be always be stuck mentally "small" in a "big" container. I don't think that would be too much fun. 

Anyway, this post is running long, so I'll cut it short here. 

Questions? Comments? I'd love to see what you're thinking!

In mind, body and spirit,

Will

Basic Training Series: Nervous System Principle #6: UNIFORMITY WITH VERSATILITY

Okay, #6 Principle courtesy of Dr. Jay Angevine,

Uniformity with Versatility
The vertebrate nervous system is accurately and reproducibly assembled. In animals of like genus and species it appears almost identical, although this is not absolute when genetic histories differ. Minor variations in the size of components and arrangements of cells are seen between species, striking ones between classes, orders and families. Yet basic regions and properties, cells and circuits, and overall organization are sufficiently alike to permit instant recognition off the basic brain plan and insights as to what these parts and cells contribute to function. Humans show increases in brain size and regional elaboration, numbers of neurons and prominence of certain connections, variations in cerebral sulcation, hemispheric asymmetry, and long projections."

Interesting principle to say the least. Here's what I got from it:

1) It looks like VERTEBRATES basically have the same nervous system plan. BASICALLY. Of course there are going to be differences but it shows how similar we are to other species, especially mammals. 

My friend, Diane Jacobs, PT wrote a little more on this, and I want to post it here because I could not have said it any better. In it she describes how little "bits" were added by nature throughout our evolution  and why we have the same basic nervous system plan as other creatures, great and small. Thanks, Diane!!

Once nature came up with a way to do something at a cellular level and this cellular model survived all the predatory and thermodynamic slings and arrows, it became handed down more less intact. Neurons are highly useful, but expensive metabolically; once a working model became established it became highly conserved, replicated endlessly in all manner of species filling all manner of niches, each species phenotype using the basic neuron model in endlessly inventive ways.

As creatures evolved, bits got added to the nervous system, but nothing was ever really deleted from it. As a result, we share basic neuron structure design with animals that date back to the days prior to the division that occurred between vertebrates and our invertebrate cousins on the planet - everything considered "animal" has neurons, except for sponges. The list includes radially symmetric jelly fish, starfish, etc., insects... - all have neurons (i.e., we humans are not "special" for having neurons, but our neuron number and arrangement is - "specie-al" to humans).

As evolution proceeded our (really ancient animal) ancestors found their neuronally equipped selves becoming bilaterally symmetrical, better for getting a grip on the world to haul a little body physically perhaps, but requiring more hard drive to coordinate two sides. So the nervous system found itself clumped up a bit at one end. After that it was probably just more economical for special senses to evolve where there was already extra hard drive built in. 

Everything after that, all the way to us, is a result of addition rather than truly different body plan. Apparently no other types of body plan were able to make it in the real world of predation and thermodynamic forces. So we share our bilaterally symmetric body plan with all other primates, quadrupeds, land vertebrates, and sea vertebrates including fish, who "invented" backbones and spinal cords, and everything else all the way back through time to whatever represents the fork in the road that led to worms on one side and fish ancestors on the other. Although worms lack a vertebral arrangement or any bones for that matter, they do have a bilaterally symmetric body plan, neurons, and a little "brain", up in front, to run all of it. 

Questions? Comments? I'd love to hear from you.

In mind, body and spirit,

Will

Basic Training Series: Nervous System Principle #5: PURPOSEFULNESS

Now we turn to Principle #5: PURPOSEFULNESS.

Here is another except from Dr. Jay Angevine's writing from the Encyclopedia of the Human Brain.


"The Purposefulness of Neural Components
Every part of the nervous system has at least one function, often many more. Small parts of the CNS may play crucial roles, as in the extensive distribution and profound influence of axons from inconspicuous brain centers. The locus ceruleus ("blue spot") on each side of the fourth ventricle contains about 12,000 large melanin-pigmented neurons. These synthesize norepinephrine and release it in the cerebral cortex, cerebellum, and almost every other part of the CNS. Electrically, they are almost silent in sleep, hypoactive in wakefulness, and hyperactive in watchful or startling situations. They serve vigilance and attention to novel stimuli. They contribute, indirectly but no less crucially, to perceptual and cognitive functions. By contrast, immense structures make large but expensive contributions, as in the cognitive and motor abilities afforded us by the billions of neurons in our cerebral and cerebellar cortices."


Even though the above paragraph is shorter, it's no less important to understanding that the EVERY part of the nervous system, has a purpose to it. No matter how small. Here are some things I picked out of it.

1) As I stated before, everything from the smallest "part" to the largest has a purpose or several purposes that we CURRENTLY know of; however, I am willing to bet that changes frequently as the science delves deeper into the NS.

2) I think a lot of folks concentrate on either the peripheral or central nervous systems but it seems that EACH part of each system (which is MANY) has a purpose and together those purposes start to add up into something that we really do not fully understand. Just my humble opinion.

3) The example about the locus ceruleus was great as it gave insight to how a small part affects the overall organism. This "small" part releases a very important chemical into critical areas of the brain which are charged with larger tasks like cognition and perception. Whoa. So what happens when one of these "small" parts stops working? Hmmmmm.... chaos maybe? For instance, the locus cereleus secretes norepinephrine in the brain, and its main function is directing attention to novel and potentially challenging stimuli.  Recently, they found that the LC also suppresses neruo-inflammation in the brain through the norepinephrine secretion. This is important in Alzheimer's Disease as there is a progression of the disease after the destruction of the LC.  The cognitive decline is well documented, so we see how small parts affect the whole.

4) Finally, the author informs us that the immense structures "make large and expensive contributions" like thinking and moving. Pretty important! Diane Jacobs, PT, always remarks how the nervous systems makes up 2% of the body BUT utilizes 20% of all resources in the body. If someone wants to debate the PURPOSEFULNESS of the nervous system, I'd like to see them do it without their cerebral cortex. ;-)

Pretty cool, stuff, huh????

I hope you are getting excited as I am about the Nervous System. The next post is Principle #5: UNIFORMITY WITH VERSATILITY.

Questions? Comments?

In mind, body, and spirit,

Will

Basic Training Series: Nervous System Principle #4: SPECIALIZATION

Okay, here we are at Nervous System Principle #4: Specialization. Lots of rich info here and a bit of foreshadowing into the complexity of the system.


"Specialization"
Reflecting its diverse tasks, the nervous system is specialized, from the single neuron to each brain region. Specialized subsystems analyze sensations. They differ in some ways, but data processing is progressive and networked in all. Neurons and the neuroglia have special shapes and roles, but both enjoy all criteria for cells and work in concert. Less obvious but equally specialized are subsystems for other functions: sleep-wakefulness, alertness, attention, affect, collating pages of a report, reading out loud from a book, self-awareness, brain damage control, and so on ad infinitum. 

Ubiquitous specializations include those for high nerve conduction velocity (large axon diameter, thick myelin sheath), space-saving bundling (small-axon diameter, thin myelin sheath, shared sheaths), short latency response (monosynaptic reflex), staggered, persistent latencies (parallel side chaining of long-axoned neurons), dependability (neuron redundancy), feature analysis (parallel processing), effect monitoring (feedback circuits), and force multiplication (feed-forward circuits). The neurons performing such tasks and the neuroglia backing them up are as specialized as these many diversified services. For neurons and the neuroglia, form indeed reflects function."

Now, this is just getting interesting! Looking at the paragraph above, I had to stop and do a little research about these specialized subsystems. To be honest, that will take SEVERAL posts and not something I want to go into now because ...well, I don't understand it fully. Later on that. 

Anyway, here's what I gathered from this excerpt:

1) The nature of the Nervous System is diversity in its activities, so this necessitates subsystems that are delegated for each task with the accompanying specialized "equipment" of neurons and neuroglia for support. 

2) Different subsystems analyze internal and external sensations. 

3) Even though the neurons and neuroglia (support staff for neurons) have different shapes and sizes, they are still cells and work together for the greater good of function. 

3) The nervous systems subsystem tasks are numerous and make up activities like wakefulness, brain damage control, alertness, attention, etc. 

4) The second paragraph gets into the specifics of how the specializations are combined and their resultant activity like feed forward and feedback circuits. We see how this is vitally important to the entire body in terms of organism survival and homeostasis. 

Another WOW moment for me as this Principle  touches on how the nervous system is ORGANIZED so that it can carry out functions. 

As promised, I'm keeping these posts shorter. 

Lookout tomorrow for Principle #5: PURPOSEFULNESS

Questions or comments, please let know.

In mind, body and spirit,

Will 

Basic Training Series: Nervous System Principle #3: Centralization

A PRINCIPLE is defined as "a comprehensive and fundamental law, doctrine or assumption." These principles are necessary to have a simple perspective of a very complex system. As I have started to learn more about the Nervous System, I have found that remembering these 8 Principles has made it easier to get through complexity to the simplicity of it all.

Here is Dr. Angevine's Third Principle of the Nervous System:

CENTRALIZATION

"The key feature of the nervous system is centralization. It offers few circuits for local interactions of body parts. The CNS is almost always involved even if the distance, as from thumb to index finger, is slight. Intercession of the brain and spinal cord ensures integrated and coordinated activity. 

Exceptions are instructive. The local cutaneous response to irritating stimuli (raking a blunt probe over the skin) has three components: local reddening (vasodilation from injury), wheal formation (transient edema from tissue fluid extrusion), and ensuing vasodilation (flare) with lowered thresholds and increased sensitivity to pain (pinprick). The flare and hyperalgesia represent an axon reflex. Nociceptive (pain) nerve endings are activated by substances released by injured tissue cells, and nerve impulses are conducted a short way centrally along nociceptive axons and then distally over branches of these axons to nearby arterioles, causing them to dilate. Advanced or primitive (it is sluggish, starting in about 20 sec. and developing fully in around 3 min), this reflex involves local nerve fibers only, not the CNS.

The "triple response" illustrates three concepts. Pain receptors sense chemical, as well as mechanical and thermal stimuli. Their sensitivity is increased by substances accumulating in the damaged area. Their response includes a neuroeffector component. They release substances (peptides) that initiate further events, providing further protection and favoring local tissue repair. 

Studies in invertebrate neural systems show extensive local control of visceral function. Exceptions to central control are also found in the mammalian ANS. Near-normal interaction of bowel segments persists in the absence of CNS innervation. Sensory fibers from the gut exert feedback in intramural autonomic ganglia on visceral motor neurons regulating smooth muscle in the intestinal wall. The nervous system has pattern generators, both central and peripheral: systems with cellular, synaptic, and network properties (cyclic firing rhythms, reciprocal inhibition of cell pairs, leader and follower cells) that provide automated mechanisms for generating rhythmic movements (breathing, walking) or periodic activities (sleeping, waking). Regulated by neural (sensory feedback, volitional override) or neuroendocrine influences, pattern generators are pithy examples of neural endogenous activity." 

Okay, looking at the above passage, I was a little confused for a bit but simplicity bit me in the backside again. Here's what I got out of it:

1) MOSTLY everything gets reported to and controlled by the central nervous system with a few exceptions which are important and "instructive" as Dr. Angevine says.

2) Regardless of distance in between two segments, the CNS is still involved.

3) The exception of when the CNS is not involved is something like a scratch to an arm that creates a local response of reddening, swelling, warming all which creates a stimulus to the nociceptors which CAN create the experience of pain. Since there is a local "axonal response," there is no requirement of integration and permission from the CNS. Given the givens, I can see why this is evolutionarily necessary. The body is going to, first and foremost, deal with survival as efficiently as possible, so including the CNS in an injury like that would be less than necessary initially. Eventually, it gets to the CNS though. Please don't forget that.

4) The enteric or "gut" nervous system does not require CNS innervation to function.

5) The nervous system has pattern generators that allow it to function efficiently and effectively that are regulated by neural or neuroendocrine influences.


That's enough for now. Stay tuned for the Principle #4: SPECIALIZATION.

I'd love to hear from you. Please let a comment or question.

In mind, body and spirit,

Will

Basic Training Series: Nervous System Principle #2: UNITY

A PRINCIPLE is defined as "a comprehensive and fundamental law, doctrine or assumption." These principles are necessary to have a simple perspective of a very complex system. As I have started to learn more about the Nervous System, I have found that remembering these 8 Principles has made it easier to get through complexity to the simplicity of it all.


Staying with Dr. Jay Angevine from the Encyclopedia of the Human Brain, we are now at Principle #2 of UNITY.



"Unity"
As in epithelium, all parts of the nervous system are physically coherent and functionally linked by nerves, tracts, and specified cell to cell contacts. Potentially each part communicates with all others. Some connections are direct (a two-neuron, monosynaptic reflex), whereas others involve myriad interposed neurons. Though complex, neural circuits offer total connectivity: fast, body-wide communication. Nerve impulses may originate in sensory nerve endings in any part of the body or anywhere in the system itself. Responsive activity complements endogenous activity, which is always evident in the human nervous system with its startling capacity to generate patterns of behavior and initiate events on its own. Sensory impulses, triggered by PNS primary sensory neurons, race over its nerves to the CNS, there diverging to clusters of secondary sensory neurons. Analysis begins. New impulses pass to central neurons on which related messages converge, which is a recombinant process providing integration. Other messages on stimulus modality, intensity, location, affective quality, body position and movement, visceral activity, fatigue, experience, and expectations are all integrated. Huge numbers of impulses are generated; untold numbers of synapses are activated. Almost instantly, nerve impulses that will elicit bodily responses stream out of the CNS to muscles and glands."

Wow! Wow! Wow!

What an important principle of understanding the nervous system. IT'S ALL LINKED TOGETHER! Not only is it everywhere, but it's physically coherent for maximum effectiveness. Here are some gems that I took from the above paragraph:

1) Again, IT'S ALL LINKED TOGETHER. 'Nuff said. 

2) The system is communicative in nature with every part potentially being able to talk to every other part. The mode of communication (monosynaptic reflex neuron, myriad interposed neurons, etc) may be different but the end result is TOTAL full-body communication required for action.

3) The nervous system is aware of what is going on in the body at all times and is complemented by bodily responses. Because of this awareness of activity, it is able to make decisions and carry them through for the organism.

4) Because of it's unity, information of ALL kinds is gathered from the periphery and communicated to the Central Nervous System where it is then processed/integrated and turned into action.

5) All of this processing requires MANY impulses to be generated from countless synapses from countless CONNECTIONS which almost instantly creates output of some kind to muscles and glands. 

It's easy to see why UNITY would be so vital to the nervous system as it controls everything we do on conscious and non-conscious levels. If there were a break in the unity, we would see varying levels of dysfunction and distress throughout the system.

Check back Principle #3 of CENTRALIZATION.

Questions or comments? Please do not hesitate to post.

In mind, body and spirit,

Will 

Basic Training Series: Nervous System Principle #1: UBIQUITY

A PRINCIPLE is defined as "a comprehensive and fundamental law, doctrine or assumption." These principles are necessary to have a simple perspective of a very complex system. As I have started to learn more about the Nervous System, I have found that remembering these 8 Principles has made it easier to get through complexity to the simplicity of it all.

Let's continue.

Here we are at PRINCIPLE #1 of Ubiquity.

According to Jay Angevine, PhD in the Encyclopedia of the Human Brain:

"Ubiquity
With 100,000 miles of nerve fibers the nervous system rivals the vascular system. Both pervade the body and function in harmony. By nerve impulses or circulating red and white cells, glucose, hormones and immune principles, they integrate body activity, protect the body, enhance its performance to met stress or demand, promote its growth and nutrition, and maintain its tone and vigor. The trunk and branches of both systems reflect body form. If either system and no other part of a person were visible, he or she would be recognizable. Density of innervation varies as the value of parts to sensory discrimination or motor control. In well-innervated areas (lips, fingertips) stimuli are sharply discriminated as to modality, intensity, and location, but in sparsely innervated areas (flanks, legs) these are less defined. Similarly, muscles vary in the ratio of motor neurons to muscle fibres. The higher the ratio, the more precise the control of the muscle and the movement it serves (a motor neuron may excite 2000 muscle fibers in a limb muscle or as few as 5 in extrinsic ocular muscles)."

Here's what jumped out at me: 

1) There are A LOT of nerve fibers in the body. Literally everywhere so there must be something to it, and if we ignore it, we are ignoring a HUGE component of the body. 

2) The nerve fibers and the veins/arteries pervade the body and work to keep the body in function and harmony. 

3) The body will have more or less nerve fibers in a particular area based on sensory discrimination or motor control. 

4) In highly innervated areas, sensory input will be distingushed shaped by modality, location and intensity. 

5) In lesser innervated areas, the sensory input discrimination will be less.

6) For finer movements, the ratio of motor neurons to muscle fibre matters since a smaller innervation ratio will resort in more subtle control. For instance if there is a 1 motor neuron to 5 extrinsic ocular muscles, there will be more control. Large motor neuron to muscle fibre ratio, for instance in the thigh muscles (1:2000+), will be the opposite, as far as motor control goes.


So where does this leave us?

Honestly, that is a lot to take in and will greatly help understanding when we start getting into the nitty-gritty of sensory input and motor output in regards to movement (therapy and training/conditioning). Getting into which structures do this is important; however, going in with the principle that the nervous system ubiquitously manages input and output of the body is powerful.

Questions or comments? I'd love to hear from you.

In mind, body and spirit,

Will

Basic Training Series: Introduction to the Nervous System: PRINCIPLES

Well, I am back! It's been MANY months since I wrote something in the blog and to be honest, I missed it.

Anyway, I am back and wanted to get into writing something that is near and dear to me: THE NERVOUS SYSTEM. Don't worry. This wont be the only thing I write about but it will be among the central topics that I write about. It's my blog. I can do whatever I want. hehe

Okay, let's get to it:

(Before I begin, I want to PROFUSELY thank Canadian phyiotherapist, Diane Jacobs, for helping me understand this complex system. Hopefully, ONE DAY, I can have an iota of her profound knowledge of the system. THANK YOU, DIANE!!!)

 Here are some quick facts about the Nervous system according to Jay B. Angevine at the University of Arizona written in the 4-volume Encyclopedia of the Human Brain, 2002, edited by V.S. Ramachandran. 

• 100 billion neurons of 10,000 types, 
• 1-10 trillion neuroglial cells, 
• 100 trillion chemical synapses, 
• 160,000 km. of neuronal processes, 
• thousands of neuronal clusters and fiber tracts, 
• hundreds of functional systems, 
• dozens of functional subsystems, 
• 7 central regions
• three main division

Wow! That is a lot to take in, so given the sheer volume and complexity of it, I can see why it's so hard to understand. In this "Basic Training Series", I'm going to try and break the Nervous System down into something that is easier to understand. Let's see what happens. 

BASIC PRINCIPLES OF THE NERVOUS SYSTEM

Jay Angevine writes about the 8 Principles of the Nervous System in the Encylopedia of the Human brain. They are:

1. Ubiquity
2. Unity
3. Centralization
4. Specialization
5. Purposefulness
6. Uniformity with Versatility
7. Plasticity
8. Chemical Message Coding

I am working to keep my writing short these days so I'll go through all eight in separate posts. 

As always, if you have any questions, please do not hesitate to ask. 

In Mind, Body and Spirit,

Will