Discover Movement Series: Humble Beginnings (Embryology)

Movement is life. From the time we as humans are conceived until the time we die, and then some, we are constantly in motion. However, this motion may not always be evident to the naked eye. In this post, I will look at our humble beginnings, or embryology, to set the stage for a life long journey of movement.

I am not going to go into too much detail except outline the later stages of human embryogenesis with links so that you are able to read through it if you so desire.

After cleavage, the morula (dividing cells) become blastula (hollow ball). The blastula, after some time, develops into a more differentiated structure called the gastrula.

From here the gastrula and primitive streak, which determines our body symmetry, starts to differentiate even more by germ layers.

The first layers are the ectoderm and endoderm followed by the mesoderm.

From there, we start to get a real picture of where the body is developmentally. The ectoderm eventually becomes the nervous system and skin. The endoderm becomes the organs and the mesoderm becomes muscles, bones, ligaments, fascia, etc. It's important to remember that the ectoderm is first developmentally [1] and this will keep resurfacing as I believe that the key to the body is the ectoderm/nervous system as it is the first in order developmentally as well  controls what will become organs and muscles/fascia/bones. 

I will stop here as I would like to keep these posts short and sweet. 

Will

References: 

[1] Mayo Clinic medical neurosciences: organized by neurologic systems and levels. 5th edition/ editied by Eduardo E. Benarroch...[et al.] 

Discover Movement Series

Well, I have not posted here in quite some time for a number of reasons that I will not go into. The most important thing is that I'm back and I have A LOT to say. However, I 'm going to keep this post short though. 

What I plan to do over the next few weeks is write about, among other things MOVEMENT. I have started on a journey of looking at movement from a very neurophysiological standpoint. Yes, the structure is important but where my studies and research has taken me is that bones, joints, muscles, fascia, ligaments and tendons are essential effectors of the Nervous System. In this series I will outline why. 

Movement is absolutely essential to life and is an exceedingly broad topic, so I will limit it to the areas of physical rehabilitation and performance enhancement. My guiding theory is based on Melzack's Neuromatrix Theory and how movement is an multi-factorial output of the Nervous System. 

I look forward to writing about this series as it is the culmination of what I have been thinking about and implementing for several months now. 

Best,

Will 

Basic Training Series: Nervous System: Peripheral Nervous System

Here's another quickie post on the Nervous System focusing on the Peripheral Nervous system.

Quick facts:

- All spinal and cranial nerves transmit information to the CNS
- 12 cranial nerves are all specialized. Some only send info, some only receive info and some are mixed

    I     - Olfactory
    II    - Optic
    III   - Oculomotor
    IV   - Trochlear
    V    - Trigeminal
    VI   - Abducens
    VII  - Facial
    VIII - Auditory
    IX   - Glossopharyngeal
    X    - Vagus
    XI   - Accessory
    XII  - Hypoglossal

- 31 pairs spinal nerves are mixed afferent and efferent

- Spinal nerves are formed by the joining of dorsal and ventral roots and contain somatic and autonomic motor and sensory nerve fibers

- Fibers of the anterior divisions or ventral rami supply the antero-lateral parts of the trunk and limbs

• - For the most part are larger than the posterior division/dorsal rami
• -Fibers extend to the limbs to form PLEXUSES.

• Cervical 
• Located from C1-C4
• Brachial plexus: 
• Located in axillary region
• Redistributes fibers to the major nerves of the upper extremites
• Median
• Ulnar 
• Radial 
• Axillary
• Musculocutaneous
• Lumbosacral plexus:
• Located in the lower abdominal cavity and pelvis
• Redistributes the fibers to the major nerves of the lower extremities
• Femoral
• Obturator
• Sciatic
• Tibial
• Peroneal

- Fibers of the posterior divisions or dorsal rami 

• Carry visceral motor, somatic motor, and sensory information to and from the skin and deep muscles of the back
• Are distinct from each other
• Innervate a narrow strip of skin and muscle along the back at the level from which the ramus leaves the spinal nerve

Well, that's good for now. Lots of info to process but very pertinent. 

Questions? Comments? Let me know.

Will

Basic Training Series: Nervous System: Central Nervous System

The Nervous System has 3 main divisions. They are:

- Central Nervous System
- Peripheral Nervous System
- Autonomic Nervous System (which has 3 sub-divisions: 1) Sympathetic 2) Parasympathetic 3) Enteric)

In this post, I will summarize the CENTRAL NERVOUS SYSTEM (CNS).

The CNS is composed of the brain and spinal cord.

Briefly about the brain....

- evolved from 5 vesicles in the cranial section of the neural tube
- vesicles are bilateral, mostly symmetrical and specialized

- 5 vesicles are:

• Cerebral Hemisphers
• Diencephalon
• Mid Brain
• Pons
• Medulla
• *Cerebellum (should be 6th region)

- interconnected by a 4 chamber ventricular system with connecting aqueduct 

Briefly about the spinal cord....

• thin, cylinder like structure
• attached to the brain 
• 5 sections with 31 segments 
• Cervical (8 segments)
• Thoracic (12 segements)
• Lumbar (5 segments)
• Sacral (5 segments)
• Coccygeal (1 segement)
• Each segment has a pair of spinal nerves
• transmission of sensory information to the brain
• regulation of motor and autonomic functions

QUICK OBSERVATIONS:

1) The brain is VERY COMPLEX. Just knowing those 6 regions will take some time but basically it IS the control center of the body. My friend, Peter, likes to call it the President of the body. It's not so much a king because others systems have a lot of input and say of what happens with the body but in the end the President makes the decisions along with input from others. 

2) The spinal cord is the super information highway of the nervous system, and it also mediates motor and autonomic functions; but it still has to answer to the brain in the final say so. 

Well, thats enough. Just wanted to keep these short and sweet. 

I'd love to hear from you with questions or comments. 

In mind, body and spirit,

Will

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