Studies in the Osteopathic
Basic Principles: Volume
Louisa Burns, M.S., D.O., D.Sc.O.
NOTHING BETTER THAN ITS NORMAL ENVIRONMENT CAN BE GIVEN THE
principle is recognized as absolute in connection with the lives of protozoa.
Among higher animals, however, there are occurrences which at first view
seem in conflict with it. It is the function of this chapter to discuss
those occurrences which harmonize with the principle as stated at the head
of this chapter, and also those which are at variance with it, either in
appearance or in significance.
The phenomena of regeneration are of interest in connection with this aspect
of the biological basis for rational therapeutics.
nature and conditions of the regeneration of lost and injured parts have
been investigated by a number of biologists, as these phenomena are displayed
both by simple organisms and by those of more complex structure, including
mankind. The investigations into the reactions of the simpler animals
have added most to our knowledge of the processes of regeneration.
This is due in part to the greater ease of investigating their physiology,
in part to their greater capacity for regeneration, and in part to the
greater simplicity of their life processes under both normal and abnormal
effects of variations of temperature upon the regeneration of lost and
injured parts has been studied by many persons. Even the most superficial
resume of these experiments would require too much space in such a volume
as this. Without any significant exception it is found that the limits
of temperature at which normal growth may take place, represents also the
limits of temperature for regeneration. The temperature which is
the optimum for any animal during the time of its most active growth is
the optimum for the most rapid and perfect regeneration of its lost and
regeneration which occurs in a worm, Planarian lugubris, has been investigated
by Morgan with significant results. The effects of starvation upon
its regeneration were first studied. This animal is very well adapted
for this work, since it endures starvation remarkably well. The planarian
is able to live until it has been starved to one-thirteenth its normal
a planarian is cut into two equal pieces by a sagittal lengthwise incision,
both pieces regenerate their lost parts, and two complete and normal worms
are formed. In Morgan’s experiments, one such half was kept well
supplied with food, and the other was kept without food. The well
fed half regenerated the lost parts rapidly, and the resulting individual
was full grown and normal. In the starved animal, regeneration proceeded
very slowly, and the resulting animal was very small, much less in size
than the half immediately after the operation. It appears that this
worm is able to reform its lost parts from the tissues which remain normal.
It is shown also that the presence of a normal supply of food is essential
to the most rapid and perfect regeneration.
there are animals in whom the beginning of regeneration occurs more quickly
during starvation than during full feeding. This is probably due
to the fact that the material from which the new organs are to be formed
is derived from the pre-existing protoplasm in the case of the starving
animal. This material is more nearly of the chemical form of the
new molecules than are the food stuffs which are probably used, in part
at least, for the rebuilding of the lost organs by the well fed animal.
effect of light upon regeneration has not been well studied. In the
case of a hydroid, eudendrium racemosum, Loeb found that hydranths were
regenerated in light but not in darkness, in blue light, but not in red.
This hydroid is one of the few animals known in which light has an influence
upon the direction of growth. It is, so far, the only one known in
which the regeneration of lost parts is influenced by light. That
is, in this animal, the same conditions of light which are best adapted
to normal growth are also best adapted to the regeneration of lost parts.
supply of oxygen is essential to normal growth and function, and is also
essential to regeneration. If the stem of a tubularia, for example,
is suspended so that it rests just above the surface of the sand, where
the oxygen is somewhat deficient, the process of regeneration is either
hindered or lacking altogether. If the stem is placed in a tube which
it fits rather closely, regeneration usually does not occur at all.
These points have been demonstrated by several investigators independently.
animals who rejoice in the possession of a nervous system, regeneration
often depends to a certain extent upon the nature of the nerve impulses
to the injured locality. Several biologists have found that when
the eye only is cut from the eye stalk of certain crustaceae, (Palaemon
and Sicyonia and one or two others), the eye is regenerated, but when the
eye stalk is entirely removed an antenna grows in the place of the eye.
This is held to be due to the fact that when the eye alone is removed the
optic ganglion is left intact and the eye regenerated, but the removal
of the entire eye stalk carries with it the ganglion, and the simpler structure,
the antenna, is developed. Or, the regenerative attributes of the
cranial structures are ordinarily effective in producing antennae,
but the influence of the nerve impulses changes the character of these
regenerative efforts in such a way that the eye is produced instead.
In any event, the normal regeneration of the eye depends upon the maintenance
of the nerve impulses normally sent to the eye.
among human beings, the regeneration of a nerve trunk is facilitated by
the maintenance of normal nutritive conditions in the area of the normal
distribution of the nerve trunk affected.
whole process of regeneration, recovery and hypertrophy are as much of
a mystery as are all other physiological processes. It is not at
present possible to offer any adequate theory for the explanation of the
effects of nerve impulses upon regeneration.
our own bodies, physiological regeneration occurs only to a slight extent.
The most conspicuous example of physiological regeneration is displayed
in the continual renewal of the continually wasted epithelial cells.
Normal Environment Facilitates Healing of Wounds.
or accidental regeneration occurs after injury to the skin, and to certain
other structures. Only small areas of skin can be regenerated, but
large areas may be healed by the multiplication of the cells of the connective
tissues. In order to facilitate the renewal of the injured skin,
the environment which facilitates the normal growth of skin is most effective.
Normal skin cells which are undergoing the processes of reproduction are
protected from bacteria and all irritating substances by the old, dead
cells of the upper layers. In order to render growth of the new cells
most rapid and normal these conditions must be secured. The injured
part must be protected from bacteria and irritants, as are the cells growing
under normal conditions, and the heat, blood supply, etc., must be kept
as nearly as possible the same as are present under normal conditions.
healing of all injured tissues, of broken bones, sprained joints, bruised
or cut, torn or burned tissues anywhere in the body is facilitated by those
conditions which are normal to those tissues during their period of growth.
Regeneration in the Nervous System.
number of neurons is fixed at a very early period of embryonic life.
There is, so far as our present knowledge goes, no possibility of regeneration
of nerve cells as such. There is a possibility of the development
of embryonic cells, however, and thus the recovery from injury to the nervous
system may be symptomatic, though it can never be absolute. The number
of embryonic cells potentially capable of development is almost inexhaustible,
under our present conditions of life. The processes of differentiation
which rendered the neurons so irritable and conductible render them also
incapable of reproduction. It did not render them altogether incapable
of regenerating their own lost parts, however. The axons which are
supplied with both the neurilemma and the white substance of Schwann may
be regenerated after section, if conditions are favorable, and they may
then perform their functions in a fairly normal manner.
a nerve trunk is injured, the regeneration of its fibers may be rendered
more certain, more perfect, and more speedy by securing the following conditions:
ends of the nerve must be sutured. If the injury is an old one, the
ends must be freshened; if the nerve has been crushed, the crushed part
must be removed. Transplantation may be employed if necessary.
blood supply to the nerve both above and below the injury must be kept
free, both upon the arterial and the venous side of the circulation.
blood itself must be kept good, by good food, good air, and good elimination.
condition of the structures normally supplied by the injured nerve must
be kept normal. This is very essential in the case of the muscles.
They must be stimulated to a normal amount of exercise, in order that they
may not atrophy. Not only is this done for the sake of having them
normal when the connections are made, but their activity seems to exert
a favorable influence upon the growth of the developing nerve fibers.
is evident that the factors which exert the most favorable influence upon
the regeneration of the nerve fibers are just those which exert the most
favorable influence upon normal growth and function.
Normal Environment Facilitates Recovery.
within the body may be injured by various abnormal conditions in their
environment. If bacteria are present, the cells which are in the
most normal conditions of metabolism are those which are most efficient
in destroying the invaders. If there has been injury to any part
of the body, the environment which is normal to that part of the body during
its period of growth is the environment which best facilitates recovery.
There is no such thing as a “healing application” anywhere in all nature,
except the things always present in the environment of the normal cells
of the body. The normal environment of the normal cell during its
period of normal growth is the best environment for the abnormal cell during
its period of repair.
Surgery, in The American Text Book of Surgery.
of Wounds, in any good text book of pathology.