Illustrations by Andrew Mannie

Originally published in Massage & Bodywork magazine, February/March 2004.
Copyright 2003. Associated Bodywork and Massage Professionals. All rights reserved.


The Anatomist's Corner is in the middle of a mini-series on the nature of membranes. Last time, we explored the nature of the cell membrane in general, and we focused on the two kinds of important proteinous links that span it. Both of these links give each cell a direct conduit to information outside the cell, and organize the function of the cell in relation to its environment via the flow of that information. These are, in shorter words, two of the cell's primary "senses." One set was the seaweed-like receptors that "taste" the chemistry around each cell in the body and use that information to decide what needs to move in and what needs to move out. These near-universal receptors, and the neuro-peptides that often fit the keys in the lock to open or close the channel, have occupied the imagination and work of Candace Pert, Ph.D., psychneuroimmunologist, among other scientists.

We also explored a newer (newer to us, that is, not the cell) class of proteins, the integrins, which link the inner cell skeleton mechanically to the outer connective tissue. The integrins "feel" the spatial or tensile environment of the cell, so that this stringy Velcro-like system amounts to the "kinesthetic" or proprioceptive sense. The integrins mediate the mechanical pulls and pushes around the cell. These forces not only hold the cell in place or cause it to move, but also can change its function and encourage it to reproduce or even die. (Stay tuned next issue for a fuller explanation of how this works and how our hands-on work affects this organismically ancient, but newly-discovered, set of links.)

Figure 1 -- The cell's two major senses -- one for taste and one feeling tension. Last issue, we described the two trans-membrane links as if they were two sets of athletes. One sorts and juggles the chemistry inside and outside the cell, in a complex and shifting dance that gets food and other necessaries into the cell, and waste and cell-products out of the cell. The other is tied to the cell's tensile skeleton on the inside and the connective tissue network on the outside.

We are now set to discuss the function of the connective tissue system as a "metamembrane" and the individual cell's relationship to it. But to understand the significance of this new concept, we first need to explore the role of differentiation and social service in a multi-cellular organism like us. And the easiest way to do that is to watch the process happen through the lens of embryology. So, bring your imagination's camera, get some good shoes on your feet and let's take a long walk back to the very beginning.


A Cell's Work is Never Done
Whether you believe in evolution or not, it is absolutely clear that each of us develops from one mother cell -- the ovum. Every time God (whether it's She or something else you believe in, doesn't matter) makes a new individual -- whether it's a human, a giraffe, a lobster or a clone -- each complex being has to go back to the beginning and build itself from a single-celled egg.

And that egg is, in fact, one "mother" of a cell: The human ovum is far and away the largest human cell there is. If you sharpen a pencil and drop it lightly on a sheet of paper, the resultant dot is about the size of the cell from which you started. Nearly visible to the human eye, this is way, way bigger than any of the trillions of other cells that make up your liver, skin, muscles and brain -- all of which require a good microscope to be seen at all. The ovum is a huge planet compared to the sperm's space shuttle, which may explain something about men's needs for ego reassurance. A chicken egg is of course an even larger cell, and an ostrich egg is the biggest single cell we know about on earth.

And what work does this cell engage in? Although you can go on answering that question biochemically for thousands of pages, functionally it boils down to six words: Metabolism, reproduction, conduction, contraction, secretion, and support (see Figures 2-7).

Metabolism (see Figure 2)-- All cells have to metabolize to stay alive, meaning they have to bring in stuff from the outside and make that stuff part of the cell, and take stuff that was part of the cell and transport it outside the membrane to the "not self." As an individual, you have to metabolize as well, and you do this every time you breath -- in comes the oxygen to become part of you, out goes the carbon dioxide (and garlic smell) that was part of you. On a slower but just as important level, you contribute to your collective cells' metabolism every time you eat or visit the bathroom. Without this exchange, no cell would be alive very long -- it would starve or sludge up in its own waste.

This process of metabolism replaces all of our molecules every seven years or so, but many parts of the body, like the lining of the stomach or the liver, have a turnover that's measured in mere weeks or months. The "hum" of activity in this regular turnover within the body is our metabolic rate, and measuring that process in "idle" gives us our Basal Metabolic Rate (BMR), which is the sum of all your cells' humming. Since metabolism burns calories, some of the work around losing unwanted weight has focused on lifting the BMR in various ways.

But this idea of taking some of the "not self," the environment, and bringing it across the membrane and turning it into part of the self, and conversely separating out part of the self and exporting it across the membrane to outside the self as waste, is a basic necessity of life for each and every cell. When the process involves more building up than breaking down, we call it anabolism (as in anabolic steroids that build muscle mass). When it involves more breaking down than building up, we call it catabolism (such as what happens to fat during the Atkins diet). Improving metabolism -- the delivery of organic materials to each cell and the flushing of wastes away into the bloodstream or lymph -- is an important benefit of both massage and movement.

Reproduction (see Figure 3) -- Most cells use this metabolic energy to reproduce copies or near-copies of themselves, either continually or occasionally, depending on the circumstances. Reproduction takes a lot of energy, as any mother will tell you for free. A number of factors, both genetic and environmental, can trigger reproduction in a cell. Basically, the cell gives half its energy, intelligence and material wealth to each of the daughter cells, and they continue to grow from there until they themselves are ready to divide.

Aside from metabolism (which amounts to self-maintenance) and self-reproduction (the biological imperative), the ovum (and cells in general) demonstrates several more abilities:

Conduction (see Figure 4) -- The cell membrane is ionized so that it can convey an electrical message around the surface of the membrane to the other side, or other end of the cell. This de- and re-polarization temporarily changes the porosity of the cell membrane, and can "alert" the cell (and by extension neighboring cells) much more quickly than any chemical message secreted by the cell.

Contraction (see Figure 5)-- The so-called cytoskeleton, or internal structural elements of the cell, contain unique proteins called myosin and actin that are capable of shape-shifting with great rapidity. The forceful sliding of these filaments past each other can move things within the cell, change the shape of the cell, move the cell in space or affect other cells around it.

Secretion (see Figure 6) -- Secretion involves bringing some chemistry to the edge of the cell and exporting it out through the membrane. We have already noted that cells "secrete" their own waste products, like carbon dioxide and urea, but secretion usually refers to other cell products. Hormones, enzymes, neurotransmitters and loads of immunity-related chemicals are produced and then secreted into various tissues by our cells.

Support (see Figure 7) -- Finally, each cell offers some support to the cells around it and to the body as a whole. This may be no more than the support a water balloon offers its neighbors, or a cell may have a rigid inner structure. Or, as we shall see, the cell may secrete substances into the space around it to support others in the area.

Specialization = Spatialize
Our ovum is a universal cell, metabolizing and reproducing like mad, and conducting, contracting, secreting and supporting by turns. The ovum divides into two, and then into four, and so on, up to the 64- or 128-cell stage (called a morula, meaning a bunch of elderberries). Then the ball expands to a hollow balloon, called a blastocyst (don't even ask) (see Figure 8).

But up to this point, all the cells are exact carbon copies of the ovum (only smaller) -- the cells do not differentiate or specialize. These cells are capable of becoming any kind of cell in the body (and hence the interest in using these "stem cells" -- usually gathered from the 8-cell stage -- for healing) but have not yet shown any tendency towards specialization. Therefore these cells are known as totipotential or pluripotential cells -- they have the potential to become many different cells, depending on their placement and surrounding chemistry to turn on certain genes.

(In fact, there are some of these pluripotential cells, especially related to the connective tissues, running around our bodies even now, although fewer and fewer as you get older. These cells stay in their unspecialized state, and are used as emergency reserves for any of these multiple types of connective tissue cells, including white blood cells, fat cells, and bone, cartilage and fiber-making cells. Such "emergencies" as spiky fevers, binge-and-purge dieting and auto injuries all use up the supply of these extra stem cells, leaving us a bit more vulnerable to stressors.)

After the cell mass expands into a blastosphere, the embryo then turns itself inside out (kind of like reaching in and pulling on the toe of a sock until it reaches the top). This process produces an inner layer and an outer layer to the embryo. At this point, specialization (and spatialization) begins. These totipotential copies of the ovum have to stop playing and start buckling down to their jobs. But what are their jobs?

Well, look at the list of six jobs above. The first two are mandatory, like math and grammar -- no cell escapes those jobs. But the last four -- conduction, contraction, secretion and support -- these are electives and that's where the variations come in. As cells specialize (and there are thousands of different kinds of cells in your body, so we are painting with broad strokes here to cover only the four main categories), they tend to emphasize one of these last four functions, often at the expense of the others.

Who specializes in conduction? Nerve cells, obviously. Nerves are fabulous at conduction, slamming messages down the membrane from one end to the other at speeds varying from 4-170 miles per hour. Nerves also change their shape to make this conduction more effective, either elongating (some individual nerve cells in your sciatic nerve are almost a meter long) or expanding their webwork out in complex ways so that their conduction affects, or is affected by, hundreds or even thousands of other nerves (as shown by the Purkinje cells in your cerebellum).

Now, being such good conductors means that they lose out on the other functions. Nerve cells are lousy at contraction, having little myosin and actin in their cytoplasm, and even lousier at support. Our living brains are like custard. The brain you see Igor carrying in the Frankenstein movies must be a preserved one. A real living brain would simply melt through Igor's fingers. Nerves do have some secretions, of course, in that the end of the conduction process results in some secretion of neurotransmitters across the synapse to start the next conduction. But generally, nerve cells favor conduction over the other functions.

Being a good conductor is so absorbing that nerve cells reduce or even lose their ability to reproduce (which is why nerve diseases or damage is so hard to repair after strokes or cerebral palsy). A lot of the work with stem cells centers on how to reproduce new neurons that could be put in place and take up the load on damaged or absent nerves in Parkinson's and other neurological diseases.

How about contraction? No news here for massage therapists -- it's the muscles, of course. Filled with myosin and actin, the muscles -- smooth, striated or cardiac -- are masters of contraction. They are not so bad at conduction either -- a signal from a neuro-muscular junction spreads rapidly over the cell membrane, activating the muscle and even nearby cells as well. Muscles don't secrete much besides their own waste (like lactic acid), and the support they offer is mainly due to turgor -- the "water balloon" type of support.

And secretion? The real specialists here are the epithelial cells that line every tube, sack and cavity in the body. These guys are the masters at making substances within the cell and pushing them out into the surrounding space. All the hormones and hundreds of enzymes necessary to coordination of physiology and digestion of food are produced by these busy little factories. They are not much good at conducting, support or contraction, but they are down with secretion.

The function of support is mainly fulfilled by the connective tissue cells, which provide the support that gives us a shape and holds that shape in place. The connective tissue cells don't do this all by themselves, they do it by secreting specific substances into the interstitial space -- substances with tensile and compressive strength. The most prevalent of these substances is collagen, the white fibers of connective tissue. Imbue this collagen with mineral salts, and you have bone. Impregnate it with translucent chondroitin, and you have the rubber plastic of cartilage. All the body's building materials are made by these busy and productive cells that go around building, maintaining, and, when necessary (or in diseases like rheumatoid arthritis) breaking down this structural matrix.

More to come on this subject next time. For now, take the point that the ovum is a big totipotential cell that carries on these six functions, and that as all the millions of daughter cells of our body differentiate and specialize, they tend to emphasize one or more of these functions at the expense of the others. By the way, the conduction specialists tend to come from the ectoderm layer of the embryo, the contraction and support specialists come from the mesodermal layer, and the secretion experts from the endodermal layer.


A Dance of Balance
We can characterize the first two functions we listed -- metabolism and reproduction -- as "self-serving," in the sense that if you don't metabolize, you will die, and if you don't reproduce, your genes will "die" (at least they won't be carried on).

The other four functions in which the cells specialize -- contraction, conduction, secretion and support -- can be characterized as "social" functions, in that they are carried out in the service of the body as a whole, not especially as a benefit to the cell itself. Muscles contract so that you can sit in the chair and hold the magazine, nerves conduct so that you can see the page. Linings secrete to digest the fuel necessary to all these functions, and the connective tissues keep you from ending up as a puddle at your own feet.

Here's the punch line to all this, which I realize has had not much to do with membranes per se, but will be essential to next issue's conclusion: When you as a whole, or an area of tissue, or even an individual cell, is distressed, it tends to abandon its social function in favor of the self-serving survival functions. In other words, a muscle cell under chemical or mechanical stress will concentrate on its own metabolism at the cost of its ability to contract. A stressed out nerve cell will stop conducting properly to attend to its own survival.

After all, don't you? If the going is tough, don't you tend to drop your service to society first and hunker down with your own survival, as in canceling your service to your clients when you are sick? And your clients, do they tend to get your best work anyway when you're stressed to the max? Cells show us the fundamental wisdom of the idea that if you're interested in taking care of others, you must take care of yourself first.

Getting this balance right can be difficult. We all know people at either end of the spectrum. On the one hand, there are people who seem to be so self-centered all the time that they barely serve any social function at all, other than taking up space and kvetching. On the other hand, we have the folks who sacrifice themselves again and again ad nauseam until they are themselves nauseated and unable to help anyone, because they never helped themselves.

But our cells show us the way: Take good care of yourself regarding eating and sex, and devote the rest of your energy to serving the whole, however you conceive it. Sounds like a formula I can live with.

More seriously, this also points to a reason why we get such interesting physiological effects from the de-stressing we provide to our clients with hands-on work. Of course their diet is their business, but the nutrition that arrives at local cells can be part of ours. As our work flushes away waste and helps to deliver the nutrients from the blood system to clogged areas, cells that have been huddled up in survival mode can stretch, heave a big sigh, and then joyfully go back to their appointed function, whether it be contracting, conducting, secreting or supporting. No wonder, then, that we see generalized and gratifying physiological results from our sessions -- as the available energy increases, our cells move out from mere survival mode to social service mode, and we as a whole function better.

Make sure, then, that your own goals in this life are worthy of your cells' great sacrifice. Would your cells be happy with your life as you lived it today? Are you dancing to your blood's music?

Next time we will carry our argument to its finish by seeing how the connective tissue operates as a metamembrane.

Thomas Myers, Certified Advanced Rolfer, L.M.T., N.C.T.M.B., studied directly with Drs. Ida Rolf and Moshe Feldenkrais, and has practiced integrative bodywork for more than 25 years in a variety of cultural and clinical settings. Myers directs Kinesis, Inc., which develops and runs training courses internationally for manual and movement therapies. He served as a founding member of the NCBTMB and as a chair of the Rolf Institute's anatomy faculty. His articles have appeared in a number of magazines, and his book on myofascial continuities, Anatomy Trains: Myofascial Meridians for Manual and Movement Therapists, was published in 2001 by Harcourt Brace. Myers retains a strong interest in perinatal and developmental issues around movement. His practice combines structural integration, physiological rhythmic sensitivity and movement. He lives, writes and sails on the coast of Maine.