CNS (Central Nervous System is Sexy)

A couple of clarifying notes as relate to my most recent post on Neurons and Excitability…

Often, when one hears Central Nervous System the inclination is to think of the brain.  This is accurate but not a complete picture.  The CNS also includes a region of the spine down to about the waist line – the spinal cord.  It is important to note that the spinal cord does not extend the full length of the spinal column.

Sensory information may arrive at a wide variety of points along the spinal cord or reach the brain itself.  Information that is processed along the spinal cord without reaching the brain results in what we call reflexes.  This is why reflexive actions occur so quickly: they need not travel the length of the spine and into the brain.

Muscle Fibers and Nerve Excitability

I have spent a great deal of time dissecting cadavers this year.  This has been an amazing opportunity to learn in person about human anatomy and physiology and is deeply informative for my continuing work with clients seeking to overcome pain.  In examining these bodies, generously donated to UCSF/SFSU, I have spent a great deal of time isolating muscles as well as bony landmarks and nerve bundles.  A muscle cell, technically called a muscle fiber, is composed of interconnected proteins which contract and release.  The first part of my revelation was that each of these fibers is the full length of the muscle of which it is part.  This means that a fiber (remember, that means a muscle cell) which makes up a small part of the Rectus Femoris (the outermost of the quadriceps muscles, it runs from the pelvis down to the knee cap) also runs the full length from the pelvis to the knee.  My second breakthrough was in connecting this fact to a similar detail about nerve cells.  A nerve cell is called a neuron and the aspect of the cell responsible for transmitting electrical impulses from the body of the cell to the outputting ends is called the axon.   Note the axon of the neuron below, covered in a myelin sheath.

Nerve

When I bump my toe everything happens so fast that it is nearly impossible to tell what is going on.  The sensory neurons in my toe send a signal to my spinal cord or my brain for processing, which then facilitates either a reflex or a processed reaction to the stimulus.  Perhaps, I withdraw my toe and cradle it in pain.  The signal, as it travels in both directions, is traveling from neuron to neuron or along the axon of many neurons, from extremity to the central nervous system (CNS, see following post for further discussion of this system) and back out again.  Some of the axons responsible for conducting the impulse to and from the toe are the length of the distance from toe to CNS!  Once the signal reaches the injured extremity it excites muscles fibers which contract (too late) to bring the toe out of harm’s way.  In these contractions, remember, fibers the length of the muscle are contracting.

Given two facts – that muscle fibers run the length of a muscle and that axons may run the distance between an extremity and the central nervous system – we can begin to understand why we can experience pain in parts of the body distant from a specific injury.  Neurons begin to respond when other neurons in their vicinity are excited.  Thus a wave of signals traveling away from the CNS may excite offshoots and facilitate muscle contraction in an area not directly impacted by the original stimulus.  As part of the healing process, this interconnectivity may be utilized by subtly adjusting areas peripheral to the site of injury.

I was recently working with a client, a professional dancer, who suffered injury to his ankle some years ago.  Since that time his career has been successful but he reports always having noticed less mobility at the site of injury.  He had seen physical therapists and massage practitioners about the issue with little or no success.  He reported that these practitioners had spent considerable time working directly on his foot and ankle and wondered aloud why I was dedicating so much attention elsewhere on his body.  But consider: if muscle fibers systematically run the length of a muscle and the axons of nerves may run from an extremity to the CNS, what impact might working elsewhere i.e. on the same leg have on the point of injury?  Muscle cells that directly connect to the area may be as far away as the knee.  Neurons that directly relate the the area may end as far as the upper spine or head.  Conceivably – just given these two facts – we could have worked on his head and seen results in his foot.  Certainly, my clients saw results!

That muscle fibers and neurons can be the lengths discussed should not be taken to completely explain interconnection throughout the body.  How neurons communicate is a very active field of research.  How axons come to be a certain length is not thoroughly understood.  Nor should the story of my client be an incentive to start poking at a friend’s head in hopes of provoking a response in her foot.  It probably will only serve to get you a good swift kick.  Of course, none of this changes the two tenants of the discussion.

Next time you stub your toe, consider: where did your responses originate?

The Lives of a Cell: Notes of A Biology Watcher

The Lives of a Cell by Lewis Thomas does not contain of the exclusive scientific vocabulary one might expect from a Doctor of Medicine who was professor, chairman, and dean at some of the most prestigious hospitals and medical universities in the United States. Thomas writes not as a scientist but as a scientifically-minded poet.  The book is a slim volume which covers a great deal of territory: each of the ten chapters takes a different perspective on issues relating to micro-biology, human evolution, the natural world, the pursuit of science.  The consistent humor and delicacy with which Thomas delves into difficult issues is a primary connection between the essays’ diverse topics.

Before properly beginning the book properly I turned to a random page and read:

Watching television, you’d think we lived at bay, in total jeopardy, surrounded on all sides by human-seeking germs, shielded against infection and death only by a chemical technology that enables us to keep killing them off.

These descriptions of our fearful actions continue for a lengthy paragraph and it is only at the end of the page that Thomas begins an outright discussion of the chapter’s topics of disease and the micro-organisms held responsible.  He sheds light on human behavior as relates to germs, behavior based not on knowledge of the cells themselves but rather on our own immune responses.  Thomas elaborates on several cases in which changing our approach could achieve more productive outcomes.

Lives of a Cell covers much more than just a discussion of micro-biology, even as relates to human behavior.  In “Some Biomythology” Thomas seriously discusses mythical beasts from a diversity of cultures and casually compares what these have to teach us about the animal kingdom with what recently-discovered micro-organisms can reveal of biology to the public.

In “Ceti” Thomas discusses Tau Ceti – a nearby start which resembles our sun, the CETI (Conference on Communication with Extraterrestrial Intelligence), and the logistics of communicating with intelligent life beyond our solar system.  He revels in the potential miscommunication. What of ourselves would we choose to share with newly-found intelligent life if the beginning of our conversation spanned hundreds of years?  Our recent discoveries in science would be an embarrassment 300 years later.  He draws the reader into the realization of how quickly human society is changing, and proposes that perhaps music – Thomas favors Bach, specifically – could be our greatest ally.

Lewis Thomas’ prose are not what one might expect from the highest echelons of academia.  He is far too human and humble in his stringing together of abstract ideas; too good at reaching a broad audience.  I cannot wait to get my hands on his earlier book The Medusa and the Snail, on his many published articles, maybe even articles published by his colleagues, to discover whether the beauty of his thoughts and writing extend beyond these pages.  I hope they do.

Tango

After many years, last evening I again dabbled in the “the dance” as I once heard Argentine tango described. While I had planned to continue today’s post with further discussion of the muscular sets which the fitness industry usually ascribes to the core, I cannot help but throw in last evening’s revelations.

Other links will described more accurately and in greater detail both the general attributes of Argentine tango and the somatic-sensory experiences of the dance.  My purpose in bringing tango into the discussion is begin to broaden the discussion and understanding of thoughtlessly used terms towards definitions which may further not only general intellectual understanding but also an individual’s personal and physical experiences.

From the moment I stepped onto the dance floor last evening I knew that something in my own awareness had dramatically changed since the last time – years previously – I was a tango floor.  Without being told, I knew that the most important aspect of me in the dance was my relationship to my center of gravity.  (I attribute this new awareness to my training under Anat Baniel and will elaborate in some later post on how that training has changed my perception.)

As my friend and colleague, Pilates master practitioner Connor Aiken, has pointed out on several occasions, “center of gravity” is a term echoed in different words throughout many different traditions.  Center of gravity is how science describes the area approximately two inches beneath the navel.  Joseph Pilates described this zone as the core.  In Hinduism the same region contains the sacral chakra.

Regardless of the name, it was my own connection to this zone and through me to my partner which dictated the quality of each dance I shared last evening.  If I was not fully connected, my partner, regardless of her (or his) prior dance experience, felt it and our dancing suffered.  However, on those occasions where I wasn’t too distracted by dance floor traffic negotiations or stepping musically to pay attention to my center, I experienced a degree of groundedness and a clarity of physical communication with my partner which is unique in my dancing experience.

Center of gravity, core, sacral chakra, or one of a dozen others; what matters more than a name is how we choose to use the area.  I suspect that many on the tango floor last evening have considerable more use of their cores than do those work tirelessly in a gym to build the appearance of a beautiful abdomen.  This is not to say that building the ubiquitously desired six pack cannot run in concert with greater body awareness.  I would merely encourage exploration – not necessary just of tango – of any form of movement which allows connection to this intriguing aspect of the human body.

Beginning Discussion of “the Core”

I just came across the following definition of the concept of the core at Spring Pilates and Yoga Studio in San Francisco.

What is the “core”?
You may have been hearing this buzz word for a while now, not completely sure what everyone is talking about. The core refers to a group of muscles and tissue around the crucial area of the lower trunk and hips. This group includes the lower spine, sacrum, pelvis, and femurs. Strengthening the muscles that attach to these areas, such as the abdominals, psoas, spinal erectors and gluteals are necessary to stabilize and control this “core” area. Since the core is the foundation of all movement (kind of like a starfish, where all movement radiates out from the center), any weakness, instability or dysfunction can cause minor to severe strain and discomfort throughout the entire body.

It is a better definition than most and provides a good place to begin. Look for further discussion soon!