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While this statement is true, in the long run, it seems observed more often in the exception than in the rule. The most conspicuous deformities are associated with apparently normal functions, and slight or gross mal-positions are sometimes a long time present without attracting any attention, or any apparent interference with the functions of any part of the body. It is the place of this chapter to discuss the significance of this rule, and its exceptions, both real and apparent. The word “normal” literally means “according to rule,” and this original significance still underlies its later usage. In this connection, the “normal structure” is that which is the rule among living things, and “normal function: is that which is according to the rule of these same living creatures. The rule, in all living things, is the maintenance of the longest, strongest, and more productive life possible to its kind. The structure which makes possible the longest and most productive life is the normal structure, and the mode of activity which is maintained by the longest and most productive life, is the normal function. Both of these conditions are the result of many centuries of progressive reactions to changing environments. In the time during which life as we now know it has existed in the world, all living things have been affected by the changes in the seasons, in their food, and in their neighbors. The manner of the reply which living things make to these environal changes is the test of their right to continued existence. Thus, they have adapted themselves to the present condition of life by both structural and functional changes. That structure which is best adapted to the conditions of the environment of any organism is the structure which is normal to that organism, and that manner of living which enables an organism to derive the most energy from its environment is the function normal to that organism. Thus, both function and structure, considered in the biological sense, are what the mathematician would call “functions” of the relation between the environment and the inheritance of the organism. Under ordinary conditions, the structure of any organism is the result of the sum of its inheritance through all its phylogenetic history, as modified by its ontogenetic history. If this sum of traits is such as to facilitate its powers of deriving energy from its environment, and its powers of making a strong and rational reply to environal changes, it lives a normal existence. Under
unusual conditions, the structure of any cell or organism may become abnormal.
It is then unable to derive the energy from its environment which is required
for its normal metabolism. It s function is then also abnormal.
If that common and mysterious thing, the molecule of living proteid, be thought of as a machine, it is very evident that the normal relations of all its parts are essential to the maintenance of its normal activities. The living proteid molecule is very like a machine, as far as we now know it. The very simplest of living molecules are very complex, compared with inorganic molecules, and there are unquestionably an almost inconceivable number of varying structures of these molecules. The simplest living cell contains, beyond question, a very great number of molecules of different composition and structure. Each of these molecules may be considered as a machine for the performance of certain duties in the life history of the cell. The chemical structure of the simplest of these living molecules is unknown—while it is living—but their variations are shown by the variations in their manner of reacting to external changes. If
these complex machines are structurally inefficient, the duties devolving
upon them must be improperly performed. If the relations of the molecules
with one another be compelled to vary from that to which they are adapted,
they must be rendered more or less inefficient. In the living cell
there are groups of molecules, apparently somewhat similar, arranged for
the performance of certain functions. The nucleus is made of many
such groups, differing from one another, and yet differing in a common
manner from other groups of molecules in the cell. Any abnormal relation
of nucleus and cytoplasm causes an abnormal condition of cell metabolism.
An experiment of Gerassimow’s is very suggestive. But the influence of low temperature on the cell of Spirogyra caught in the act of dividing, he succeeded in driving all the nuclear substance into one daughter cell, leaving the other quite devoid of a nucleus. In a series of such experiments, it was seen that in twenty-one days the growth of the enucleated cell amounted to from four-tenths of one per cent to four and five-tenths of one per cent of the growth of the normal cell. That is, the most active of them all made only about one-twentieth of the normal growth, and the least active grew only one-two-hundredth part as much as did the normal cell. The growth of the other cells, with the excess of nuclear material, exceeded the growth of the normal cells by as much as seventy-eight per cent. At the same time, the solution of starch by the enucleated cell either did not take place at all, or proceeded very feebly; the outer cell membrane was less extensible than usual; the color of the chlorophyll bands became constantly paler and their contour less clear. Loeb also has made experiments in determining the effects of nuclear changes upon the activity of the cell. Nothing which affects the structural integrity of any cell is without effect upon the metabolism of the cell. There is not yet found any exception to this statement.
In multicellular organisms, every cell must maintain its structural integrity if it is to maintain its normal function. It is the cell structure that must maintain its integrity. Things which affect the gross structure of the body are efficient causes of malfunction only as they affect the structure or the environment of the cells of the tissues. This is the reason why gross deformities so often cause such slight malfunction,--the cells have remained fairly normal in structure and environment. For the most part, however, any gross structural change does affect the structure and environment of the cells themselves. Structural changes may be quickly and forcibly produced, or they may be the result of long acting forces, and be slowly caused. In the first case, the functional effects are usually intense; in the second case, the cells of the body may accommodate themselves to the slowly changing conditions, and the functional disturbances be comparatively slight. In the case of human beings the functional changes resulting from slight injuries are frequently not noticed because of the abnormal condition of nearly all bodies all the time. The human race, at its best, falls far short of the longevity, strength and beauty to which it is entitled. Failing in the perfection of function, further causes of embarrassment often remain a long time unnoticed. Another reason for the non-appearance of functional abnormalities is found in the fact that the human body has become adapted to a vast amount of ill usage, by being so constantly ill-used during its past history. The discussion of causes and the nature of the effects produced by the structural changes of the tissues of the human body belongs more properly in text books dealing with osteopathic diagnosis and therapeutics, but a short resume may serve to illustrate the principles stated in this chapter.
Abnormal structural relations may exert direct pressure upon cells of the tissues. The body contains no waste spaces; if any tissue is misplaced it must exert tension or pressure somewhere, and it must itself be subjected to tension or pressure. Any pressure upon cells produces an effect which varies according to the nature of the tissues affected. No cells are able to maintain their normal metabolism for any length of time in the presence of abnormal pressure conditions. Abnormal structural relations may partially or completely occlude the nutrient arteries of any tissue. The cells are thus starved for both food and oxygen. The effects produced are those characteristic of starvation throughout the whole living world. These phenomena vary to certain extent, but not in any essential feature. Abnormal structural relations may partially or completely occlude the venous return or the lymphatic drainage from any tissue. The cells then are forced to continue their life processes, as far as they are able, in the presence of their own waste products. No cell is able to do this,--even the unorganized ferments cease their activities under such conditions. Abnormal structural relations may exert pressure upon nerve trunks. The normal stream of nerve impulses is thereby more or less seriously impeded, and the function of the tissues affected suffers a corresponding embarrassment. Abnormal structural relations may initiate abnormal nerve impulses. These may cause conscious pain, or they may occasion reflex nerve stimulation of a more or less urgent malignancy. Secondary effects from all structural mal-adjustments mentioned are numerous. Any satisfactory discussion of these is beyond the limits of this volume.
The Osteopathic Lesion, Carl P. McConnell, D. O., M. D., in The Journal of The American Osteopathic Association, May and December, 1905, and May and August, 1906. Special Pathology of the Nerve Cell, in Mental Diseases, Henry J. Berkley. |