Studies in the Osteopathic
Basic Principles: Volume
Louisa Burns, M.S., D.O., D.Sc.O.
THE EXPERIMENTAL DEMONSTRATION OF THE OSTEOPATHIC CENTERS:
variations in the blood supply to the hands and arms have been investigated
by means of a series of experiments upon human subjects. For this
work, the plethysmograph was used.
plethysmograph is a glass cylinder provided with a rubber cuff and with
stop cocks and rubber tubes. The subjectís hand is enclosed in the
cylinder, the rubber cuff surrounds the arm, and one rubber tube leads
to the tambour, a pan covered with sheet rubber, upon which rests a needle.
The needle plays upon a revolving drum covered with smoked paper.
The plethysmograph and tambour are filled with water, oil, or air, according
to the conditions of the experiment. If the size of the hand, as
it is enclosed in the cylinder, should increase, the fluid in the cylinder
would be pressed into the rubber tube and into the tambour pan. The
rubber cover of the tambour pan would be forced up, and this would lift
the needle resting upon it. The needle thus writes the record upon
the smoked paper.
ed muscles occupy a very little less space than relaxed muscles, hence,
when the fingers are strongly flexed, while the hand is encased in the
plethysmograph, the needle is permitted to fall. But after the muscles
are relaxed, the blood flows into the hand in increased amount, and the
needle is sent up again, higher than before the muscular contraction.
Very slight changes in the amount of blood in the hand and forearm are
recorded by this apparatus.
effects of the artificial lesion and of the various stimulating and inhibiting
manipulations upon the blood supply to the arms are as follows:
of the tissues near the roots of the nerves which make up the brachial
plexus produced slight effect, and that only after a long latent period,
and with an amount of stimulation which occasioned a really painful sensation.
It appears from these experiments, that such manipulations were only indirectly
effective, probably through the sensory fibers of the brachial plexus and
the chief vaso-motor center in the medulla.
movements applied to the brachial plexus under the clavicle caused a decrease
in the blood supply to the arm, evidently by causing the constriction of
the arterioles. This manipulation was followed by an increase in
the blood supply, beyond that originally present. It appears, then,
that the brachial plexus carries the vaso-motor nerves from this point.
Anatomically, it is known that the brachial nerves receive gray fibers
from the ganglion stellatum.
manipulations to the tissues near the first second and third thoracic spines
caused no perceptible effect upon the blood supply to the arms and hands.
manipulations to the tissues near the fourth and fifth thoracic spines
caused a decreased amount of blood in the hands. This reaction must
be due to vaso-motor nerves to the hand. The stimulation of this
center is known to cause a constriction of the pulmonary arterioles, and
this must raise the blood pressure. The effect produced upon the
arterioles of the arm by this manipulation is evidently sufficiently pronounced
to overcome the effects of the increased blood pressure.
artificial lesion in the same area causes an increased amount of blood
in the hand. This, again, is directly opposite to the effect which
is to be expected if the pulmonary vaso-motors were alone active under
manipulations given to the centers below the sixth thoracic spine caused
an increased flow of blood to the hand. The vaso-motors to the hand
were evidently not themselves affected by this manipulation. The
stimulation of these centersói.e., below the sixth thoracic spineócauses
a constriction of the vessels in the liver and intestines, the systemic
blood pressure is thus raised, and the blood flow to unaffected parts of
the body is increased.
the same manner, the artificial lesion below the sixth thoracic spine caused
a decreased blood flow to the hands. That is, the artificial lesion
below the sixth causes a dilatation of the vessels in the liver and intestines,
and the blood is mechanically drained away from the other parts of the
body, including, of course, the hands and arms.
osteopathic or superficial center for the arterioles of the arms is therefore
found near the fourth and fifth thoracic spines.
a number of instances of injury to the hands and fingers, in persons otherwise
healthy, there were reflex muscular contractions near the fourth and fifth
thoracic spines. Muscular contractions near the origin of the fibers
of the brachial plexus were less constant.
some case reports of Raynaudís disease, Dr. J. L. Adams describes lesions
affecting the fourth thoracic vertebra, and he reports favorable results
from the correction of these lesions.
experiments were performed for investigating the centers controlling the
vaso-motors to the legs.
Disease, any text book of medical practice.
Disease,, McConnell and Teallís Practice of Osteopathy.
Disease, A. O. A. Case Reports.