Principles of Osteopathy
Dain L. Tasker, D. O.
CHAPTER IX - Circulatory Tissue
From the histological standpoint, blood conforms to the general
definition of a tissue, being composed of a cellular and intercellular substance.
The intercellular substance, being liquid, differentiates it greatly from other
tissues. It contains cellular elements which differ from each other in
form and function. Then, too, it is a moving tissue enclosed in a system
of closed tubes.
Functions. - The blood performs many functions.
These may be stated in general terms as follows:
1. To convey nutrition to all other tissues.
2. To remove waste products from the tissues.
3. To convey oxygen for tissue respiration.
4. To distribute heat.
5. To repel invasion of bacteria.
Lymph. - Lymph is another liquid tissue, less
rich in corpuscular elements, but greater in total bulk than the blood.
The lymph comes in direct contact with the elements of the tissues.
Stewart states the relationship tersely when he says, "The blood feeds
the lymph and the lymph feeds the cell."
Since we think of individual tissues as possessing
some one well developed attribute or function, it is well to call blood
and its congener, lymph, the media of exchange. This expression covers
at least four of the functions previously mentioned.
With this comprehensive but short statement of the
relation of these liquid tissues to the structural, contractile, irritable
and secretary tissues, it seems hardly necessary to discuss so self-evident
a proposition as that health primarily depends on a perfect circulation.
It is not even necessary to add to this the fact that the blood should
be pure, because under ordinary circumstances if the blood circulates properly
it will become purified.
All schools of medicine have a therapeutic principle
around which their practice is built. From its earliest inception
the osteopathic idea has been that a perfect circulation is the foundation
for perfect health.
The proportion of blood to body weight is about one-twelfth
of the whole, i. e., twelve pounds of blood in a body weighing 150 pounds.
This amount of blood is distributed approximately as follows: One-fourth
to the heart, lungs and great blood vessels; one-fourth to the liver; one-fourth
to the resting muscles; one-fourth to the remaining organs. There
is not blood enough in the body to maintain all of its activities at the
maximum at the same time. Therefore it is difficult to do the best
physical or mental labor just after digestion has begun. The splanchnic
blood vessels are capable of containing so large a proportion of the whole
amount of blood that death may result from lack of sufficient blood returning
to the heart to cause it to beat.
Distribution of the Blood. - Granting that
the blood possesses all these functions, the question still confronts us,
how can we affect its distribution? This question leads us to a consideration
of the physiological distribution of the blood. It is believed by
the writer that nothing besides the use of water has so great an effect
on the circulation of the blood as manipulation according to osteopathic
methods. These methods do not depend on a mere physical assistance
of the venous flow by means of centripetal stroking, such as is employed
by a masseur. Effects on circulation are obtained in nearly all cases
by knowing where definite nerves which control the action of the heart
and blood vessels are placed and what their action in response to irritation
may be. All manipulations are given with a definite knowledge of
the location of blood vessels and the nerve centers which control their
variation in caliber. The response secured is a new coordination
of the whole circulation brought about under the control of the nerve centers.
It has been stated that the blood is contained in
a closed system of tubes. A short resume of the most important points
in the anatomy and physiology of the circulation may prepare us for a clearer
insight of the modus operandi of osteopathic methods.
The Circulatory Apparatus. - The circulatory
apparatus consists of the heart, arteries, capillaries, veins and lymphatics;
some writers include the spleen.
Muscular tissue is found in the heart, small arteries
and veins. The heart is practically all muscle, and its contractions
are governed by two sets of nerve fibers from the cerebrospinal system;
the first set is called accelerator; second, inhibitory.
Likewise, the small arteries and veins have two sets
of fibers which increase and decrease the intensity of the contraction
of their muscular fibers, and thus change the caliber of the vessels.
The capillaries are short, narrow tubes, having a
thin wall composed of nucleated cells which possess the power of contraction.
So far as known, the capillaries expand and contract in response to the
degree of physical pressure exerted by the blood current coming from the
arterioles. Thus the change in the caliber of the capillaries is
passive. The lymphatics begin in small irregular spaces in the cellular
tissue outside of the blood vessels. They are found in direct relation
with the cells of perivascular tissues, thus bringing the lymph to each
cell. These openings lead to small lymphatic vessels which convey
the lymph to the lymphatic glands which are situated so as to filter out
the impurities, after which it is emptied into the venous circulation by
the lymphatic ducts. The lymphatic vessels possess power of contraction.
The lymph equals about one-third of the body weight.
The blood is a passively moving tissue. It
is kept in constant circulation within a closed system of tubes by a combination
of forces. The propulsion of the blood is almost entirely accomplished
by the contraction of the heart. This initial force is supplemented
by the aspiration of the chest during respiration, and the contraction
of the skeletal muscles of the entire body. It is a debatable question
whether or not the muscular coat of the, arterioles and venules assist
in the direct propulsion of the blood passing through them.
It is the function of the heart to maintain a comparatively
uniform tension of the blood in the large arteries. The arterioles
and capillaries are concerned in maintaining resistance to the passage
of the blood. The degree of resistance in the capillaries, in large
measure, determines the amount of nourishment received by the tissues.
The relation between capillary resistance to the passage of the blood and
the metabolism carried on in perivascular tissues is a point of great importance.
The current of blood ordinarily passes through the capillaries very slowly,
at a rate of one inch in two minutes, and under low tension, thus giving
ample opportunity for the escape of nourishing material for the surrounding
Tension in the arteries is maintained by three factors:
(1) The initial force of the heart beat; (2) friction in the vessels; (3)
elasticity of the vessel walls. The first and third of these factors
are under nerve control which act according to a large number of stimuli.
The capillaries being passive in action, the tension
of the blood stream in them is mainly dependent on the tension in the arterioles.
It may be profitably noted that after the initial impulse is given to the
blood stream by the heart, the distribution of this blood depends solely
on the arteries, arterioles and capillaries. This peripheral distributive
mechanism is therefore responsible for the nutrition of the tissues, and
its resistance offered to the passage of the blood regulates the amount
of force exerted by the heart.
Manipulatory treatments, according to the best authorities
writing on massage and Swedish movements, have for their object the acceleration
of the blood flow on the venous side of the general circulation.
Osteopathic manipulations are essentially directed to the active instead
of the passive side of the circulation.
The osteopath makes use daily of the vasomotor nerves
in order to control the circulation of the blood in local areas; therefore,
it is necessary to make a detailed study of this wonderful mechanism in
order to achieve the best results in practice.
The more we know of structure and function, the more
rational ought our methods of treatment to be, because we will then have
no excuse for using methods which do not have a scientific basis to recommend
The Heart. - In order to affect the active
side of the circulation our manipulations must affect the heart beat.
There are two sets of nerve fibers arising in the cerebrospinal system
which exert a regulating influence on the beat of the heart. Heart
muscle possesses an inherent power of rhythmical contraction. It
will beat rhythmically for hours if the muscle be kept moist with a one
per cent salt solution.
Contraction begins in the auricles and ends in the
ventricles; hence, it is thought that the auricular rhythm is transmitted
to the ventricle. Any influence which changes the auricular rhythm
also changes the ventricular rhythm.
Regulation of Contraction. - Since the heart
possesses inherent power of rhythmic contraction, the nervous system acts
as a regulator of the rate of contraction. The two centers of cardiac
control act in a manner to increase or decrease the rate. The speed
of the blood current is dependent on the rate and strength of the cardiac
contractions. The pressure of the blood is dependent on the rate
and strength of the cardiac contractions, together with the resistance
offered by the arterioles and capillaries. Considering the arterioles
and capillaries as possessing fixed diameters, an increase in the number
and strength of the heart beats would increase the speed and pressure of
the blood current. A lessened cardiac activity would have the opposite
effect. The speed and pressure of the blood stream may vary within
wide limits and still maintain a fair degree of health.
Coordinating Centers. - The nerve impulses
reaching the heart are coordinated in two governing centers in the cerebrospinal
system. These centers are located in the bulb. The inhibitory
center is connected with cells in the walls of the heart by fibers which
form a part of the pneumogastric nerve. Section of the pneumogastric
nerve removes the inhibitory influence over the heart's action. Stimulation
of this nerve slows the heart. The relaxation period is lengthened
which results in greater filling of the heart and the pressure in the veins
is increased while arterial pressure decreases. These results have
been noted by many physiologists.
The Pneumogastric Nerve. - The pneumogastric
is one of the nerve trunks which can be reached by direct pressure made
through the skin and muscles of the neck. Its inhibitory action can
be aroused by pinching the sternocleidomastoid muscle between the thumb
and forefinger, taking care to work deeply under the internal margin of
It is no uncommon phenomenon to have a patient faint
as a result of this manipulation. Individuals differ greatly as to
their response to this stimulation. The stimulation should be a gentle
pressure of a constantly varying intensity.
A pulse tracing is appended, Fig. 24, which shows
the results of stimulating the pneumogastric in the manner just described.
The gentleman upon whom the experiment was made was in excellent health,
and possessed a quiet, well-balanced temperament. The tracing shows
that the number and force of the beats was lessened and the arterial pressure
decreased. This tracing is probably typical of the change, in a well
person, in response to stimulation of the pneumogastric. No sensation
of faintness or other disagreeable feeling was noted.
The inhibitory action of the pneumogastric seems
to be most active in individuals who suffer from some disorder of the digestive
tract. In such patients the constant irritation of the sensory fibers
of the pneumogastric, which arise in the mucosa of the digestive viscera,
seems to increase the irritability of the whole nerve trunk to such a delicate
point that the slightest stimulation made at any point along the course
of the nerve will excite its inhibitory action. Many osteopaths,
just starting in practice, have had. their self-possession severely tried
by a patient fainting during manipulation of the neck. I have never
heard of any fatal results from manipulation of the pneumogastric.
Why stimulation of the, pneumogastric should result in cardiac inhibition
rather than in phenomena connected with its other branches seems incapable
of explanation. Sometimes spasm of the laryngeal muscles will accompany
The intensity of action of the pneumogastrics is
so well known to experienced osteopaths that they are careful to test its
irritableness in cases before undertaking any extensive manipulations along
The inhibitory center is continually active and acts
according to the blood pressure within the arteries. A rise in peripheral
resistance causes a decrease in number and strength of the heart beats.
Accelerator Center. - The accelerator center
is connected with the heart by fibers which descend in the cord to the
upper portion of the dorsal region; here connection is made with the cells
whose fibers pass to the sympathetic spinal ganglia, first, second and
third dorsal, and end there around other cells whose fibers convey their
impulses to the heart.
The action of the accelerator center is not so readily
demonstrated as is the case with the inhibitory center. It causes
the heart to beat faster and stronger, thus bringing about a rise in arterial
blood pressure and a fall in venous pressure. This center acts in response
to lowered peripheral resistance. The products of metabolism brought
about by physical exercise also excite it. Deep, steady pressure
made on the muscles lying on each side of the first, second and third dorsal
spines causes a decrease in the rapidity of the heart's action.
Stimulation of the Heart. - A make and break
pressure made at the edge of the sternum in the first and second intercostal
spaces,will usually stimulate the heart. Sometimes the first effect
is inhibition, but it quickly passes to stimulation. The manipulation
made anteriorly increases the number and intensity of the stimuli reaching
the segment of the cord from which the accelerator nerves pass out.
All centers act according to the sum of the stimuli reaching them from
Inhibition of the Heart. - In cases of rapid
heart beat with high tension pulse the best effects are secured by digital
pressure at first, second and third dorsal spines. The pneumogastrics
have too many branches to important viscera and act frequently with unexpected
intensity. The accelerators act more slowly with less intensity and
the action is sustained longer, that is, as a result of manipulation.
Vasomotor Control of the Coronary Arteries.
- A further factor in relation to the regulation of the heart's action
is the blood supply for the nourishment of the heart. All organs
act with greater force when their blood supply is abundant. The heart
beats stronger when its coronary arteries are dilated than when constricted,
therefore the power of the heart depends on the vasomotor control of its
own arteries. The vasomotor nerves to the coronary arteries leave
the cerebrospinal system between the third and fifth dorsal spines.
In cases of angina pectoris, this area will be sensitive. Steady
pressure here will dilate the coronary arteries and ease the pain.
A sharp stroke with the hypothenar eminence on the fourth dorsal spine
will nearly always start an attack with such patients.
Angina Pectoris. - Physiologists name the
pneumogastric nerve as the vasomotor nerve to the coronary arteries.
I mention the area, third to fifth dorsal, as a vasomotor center for the
coronary arteries because clinical experience seems to demonstrate it.
Other osteopaths have noted the frequency of lesions in this area in connection
with heart difficulties. The lesions are contracted muscles, lateral
subluxations of the vertebrae or in some instances subluxations of the
fourth and fifth ribs. With any of these lesions there is intense
Dr. George Keith of Scotland mentions digital pressure
in the second left intercostal space as a means of inhibiting an attack
of angina pectoris, and suggests the nerve connection of the pneumogastric
as being the nerve path over which the inhibitory impulse travels.
Persons suffering with angina pectoris will press their hands, with all
the force they possess, against the left chest. I have used heavy
digital pressure on the left side of the fourth and fifth dorsal spines
while the patient was in a paroxysm of pain. The pressure never failed
to be grateful to the patient.
A further experiment with this center was made by
extending the patient in a recumbent position. While extension was
maintained the angles of the ribs could be raised, the left arm could be
extended over the head, a full inspiration could be taken, but as soon
as the vertebrae were allowed to approximate as a result of cessation of
extension, these things could not be done.
Heat, digital pressure and counter irritation are
capable of causing vasoconstrictor paralysis, i. e., vasodilation, and
hence increase the power of the heart in such cases.
Action of the Heart Centers. - The governing
centers of the heart act principally according to the peripheral resistance
maintained by the blood vessels. The heart possesses a nerve called
the depressor nerve. Its endings are in the walls of the heart and
are affected by the pressure of the blood within the heart. A rise
in arterial pressure is followed by a rise in pressure within the heart.
The depressor nerve notes this fact and carries an inhibitory impulse to
the vasodilator center in the medulla, thus bringing about a fall in arterial
pressure. In this way the heart is protected from overexertion as
a result of too high pressure.
In cases having rapid, weak heart action, inhibit
the accelerators to slow the heart, also inhibit in the area of vasomotor
control of the coronary arteries to increase the amount of blood for nourishment
to the heart muscle, thus increasing the strength of the beat.
In cases of rapid, high tension pulse, inhibit the
splanchnics and in the suboccipital fossae to lessen peripheral resistance,
also inhibit the accelerators or. stimulate the pneumogastrics.
Vasomotor Nerves. - In 1840 Henle discovered
and demonstrated the muscular coat of the arteries, and as a result of
this step forward we have our present knowledge of the vasomotor nerves.
Associated with the demonstration of these nerves we have the names of
BrownSequard, Bernard, Waller and Schiff.
It has been proven that two sets of fibers innervate
the muscles of the arteries; a vasoconstrictor set, which causes a decrease
in the caliber; and a vasodilator set which causes an increase in caliber.
The constrictors were demonstrated first.
Henle said "the movement of the blood depends on
the heart, but its distribution depends on the vessels." We have followed
the phenomena in connection with the first part of this quotation, hence
it remains for us to study the part played by the vessels in the distribution
of the blood.
In order to carry our thoughts along in a proper
manner, we will commence at the center and work toward the periphery.
The chief vasomotor center is in the medulla.
Destruction of this center causes an immediate fall of blood pressure all
over the body. Stimulation of this center causes a general rise of
There are subsidiary centers situated at various
levels in the spinal cord.
After the spinal cord is severed, that portion which
is no longer connected with the chief vasomotor center will exercise a
vasoconstrictor influence over the blood vessels in its area of normal
control. "It is probable that they are normally subordinate to the
bulbar nerve cells."
After all connection between the cerebrospinal system
and sympathetic spinal ganglia is cut off, the tone of the blood vessels
is maintained, after a short interval, by the sympathetic ganglia.
By commencing at the center and destroying it, then
the centers in the spinal cord assume control; destruction of these leaves
the sympathetic spinal ganglia active; hence by this process of exclusion
we find that the true vasomotor cells are sympathetic and lie in the spinal
ganglia. From these cells in the spinal ganglia-axis cylinder processes
pass as gray fibers to blood vessels. These ganglia cells are controlled
by fibers from the chief vasomotor center in the medulla which end around
the subsidiary cells in the spinal cord, the neuraxons of these latter
terminating by filaments which surround the true vasomotor cells in the
sympathetic spinal ganglia.
Since gray rami-communicantes pass from the spinal
sympathetic ganglia to the spinal nerves and are distributed with them
to the skin and blood vessels, we can influence the distribution of the
blood generally and locally by increasing or decreasing the number of sensory
impulses, originating in the skin and muscle, which may reach the vasomotor
"The vasomotor apparatus consists, then, of three
classes of nerve cells. The cell bodies of the first class lie in
sympathetic ganglia, their neuraxons passing directly to the smooth muscle
in the walls of the vessels; the second are stimulated at different levels
in the cerebrospinal axis, their neuraxons passing hence to the sympathetic
ganglia by way of spinal and cranial nerves; and the third are placed in
the bulb and control the second through intraspinal and intracranial paths.
The nerve cell of the first class lies wholly without the cerebrospinal
axis, the third wholly within it, while the second is partly within and
partly without, and binds together the remaining two." (Am. Textbook
Vasoconstriction. - The vasoconstrictor nerves
which pass from the bulbar and spinal centers of control leave the cord
as white rami-communicantes from the anterior roots of the second dorsal
to the second lumbar nerves and enter the sympathetic ganglia to be distributed
as has been described before. It is believed that all of these vasoconstrictor
fibers end in the ganglia, thus exerting their influence on the true vasomotor
cells in the ganglia which alone send fibers to the blood vessels.
All these constrictor nerves are gray.
Vasodilation. - The vasodilator fibers are
not restricted to any one portion of the cord or brain, but pass out with
both cranial and spinal nerves, and do not lose their sheaths until they
reach their destination. They are best demonstrated in those regions
of the cerebrospinal system from which vasoconstrictors do not arise.
The vasodilators from the head, face, salivary glands, etc., pass to their
destination with the cranial nerves supplying these parts. They do
not end in the sympathetics. They probably leave the cord in the
anterior roots of the spinal nerves and pass to the periphery without interruption.
The vasodilators, leaving the cord in the same region as the vasoconstrictors
to be distributed to the visceral blood vessels probably pass out by the
ventral roots and reach their destination without losing their sheaths
in the sympathetic ganglia.
No distinct centers for vasoditator fibers have been
demonstrated. They probably arise from segments of the brain and
spinal cord and their influence is carried along the paths of motor nerves
and is exerted in a local area.
Summary. - 1. The vasodilator nerves
are cerebrospinal; (a) and are not demedullated in the sympathetic ganglia.
(b) They are distributed principally to the arteries of the muscles, (c)
and leave the cerebrospinal axis with the motor nerves from all portions.
(d) Their influence is local.
2. The vasoconstrictors are essentially neuraxons
of sympathetic cells in the spinal ganglia; (a) are gray fibers; (b) are
distributed to viscera and cutaneous blood vessels; (c) and are probably
continuous in action to maintain the tone of the vascular system. (d) The
vasomotor cells in the sympathetic ganglia can act independently, (e) but
are normally under the control of the cells in the spinal cord whose neuraxons
end in the spinal ganglia. (f) These cells in the spinal cord are under
the influence of neuraxons of cells in the medulla which constitute the
chief vasomotor center. (g) Therefore, the vasoconstrictor influence is
both local and general. (h) The controlling fibers leave the cord in the
ventral roots of the second dorsal to the second lumbar nerves only.
Sensory Nerves. - We have now considered in
detail only one side of the vasomotor mechanism, the motor. We have
yet to note the sensory side, that which calls forth the motor response.
If there were no chief or spinal vasomotor centers to transfer sensory
impulses to the vasoconstrictor cells in the spinal ganglia, the blood
vessels in the viscera and skin could not contract or relax according to
the necessity for greater or lesser amounts of heat in the .deep or superficial
The vasomotor centers in the brain and cord send
out impulses in response to sensory stimulation; this sensory stimulation
is usually of a thermal or mechanical character.
It is difficult to realize the extent of the distribution
,of sensory nerves. "They are located not only in those places usually
known to be sensitive, but also in all other tissues and organs.
Whether one examine the liver or the kidney, lung or the wall of a blood
vessel, one always finds delicate nerve arborizations in unsuspected numbers.
A large portion of them end probably in the peripherally placed end cells
belonging to the reflex arc of the sympathetic; 'another portion may very
probably be traced to the spinal ganglia, and even to the spinal cord itself,
especially the investigations of the past two years, making use of the
silver and methyl blue stains, have not only disclosed the wealth of nerves
in the different organs, but have also shown that we have regarded the
sensory innervation of the sensitive surfaces, as the skin and the much
less fully explained gustatory-mucous membrane as than they really are.
One finds there numerous plexuses of nerve fibers beneath and between the
epithelial cells, and they send one, often many, fine fibrils to each cell."
ladder, and many "In the liver, too, and the other places, one can find
numerous examples of the abundant peripheral innervation. We have
always given too great importance to the single end apparatus, overlooking
the fact that really the major portion of the body tissues is supplied
with nerves for every cell. One can hardly overestimate the wealth
of nerve fibers in the end organs themselves, as the taste papillae and
the tactile papillae. Good staining discloses with each of them plexuses
of unexpected density of arborization."
"For what services may such an abundant sensory innervation
be provided? It occurs immediately to one that there are a great
number of reflexes, very necessary to the preservation of the individual,
even though he be unaware of them. The regulation of the secretions,
the blood supply to the skin in relation to the caloric body economy of
the organism, the adjustment to varying illumination, the tension of the
muscles and tendons through the respective tendon reflexes, the different
response by such varying tensions according to the intensity of the voluntary
impulse, and many other phenomena could be cited. To all of them
is necessary, besides the motor part of the reflex arc, a sensory part.
Indeed, Exner, to whom we are indebted for indicating the importance of
these short reflex arcs and the roles they play in the organism, has pointed
out how, in general, for the production of any movement the sensory innervation
must be intact."
"By 'sensory innervation,' however, one must not
think only those processes are meant which enter into our consciousness,
but rather all those by which from any place in the body impressions are
conducted to the nearest ganglion, or to the central axis. Whether
they be conducted farther still, or whether they be recognized by the individual
as they occur does not affect their nature. Sensation and perception
are not the same thing." (Anatomy of the Central Nervous System in
Man and in Vertebrates in General. - Edinger.)
Thus we find that there are abundant sensory nerves
in superficial and deep tissue to receive the mechanical stimuli which
the osteopath may project upon them.
Recent investigations prove that many conditions
which have previously been called inflammation are, in reality, congestions
due to vasoconstrictor paralysis, and can be corrected by stimulation of
the vasoconstrictor center governing the congested area; the stimulation
of such center being secured by mechanical stimuli applied to the sensory
nerves ending in the center.
The vasomotor mechanism responds quickly to osteopathic
manipulation, and is our means of correcting any disturbance of circulation,
both local and general.
Since the blood carries the nourishment for the tissues,
and the vasomotors control the distribution of the blood, the vasomotor
nerves are trophic nerves. In the same sense they are secretary nerves.
Capillary Circulation. - The capillary circulation
is dependent on the state of the arterioles. Their walls are formed
by endothelial cells. which are elastic, and hence respond to the force
of the blood which enters them. If the vasoconstrictors are active
in a local area the resistance offered to the passage of the blood current
by the arterioles is increased, and therefore the pressure exerted on the
capillary walls is lessened, allowing the capillaries to contract.
If the vasoconstrictor influence over the arterioles be lessened, the blood
current is allowed to exert its pressure on the capillary walls, thus increasing
the caliber of the capillary.
If, in a large area of the body, vasoconstrictors
are active, the influence of this resistance is felt by the heart, which
immediately beats harder to overcome the resistance to the passage of the
blood through the constricted arteries. The heart is usually relieved
by compensatory dilatation of the arteries in some other area. The
visceral and cutaneous arteries usually counterbalance each other in this
way. This counterbalancing effect is probably brought about through
the sensory impressions sent out from an overworked heart to the vasomotor
center, thus causing a lessened constrictor effect in some portions of
The relaxation of all the arteries of the body would
cause death, because the blood would gravitate to the most dependent part,
and there is not blood enough to fill all the arteries when relaxed.
A slight relaxation of general blood pressure causes the heart to beat
more rapidly for a short time. Relaxation of the peripheral blood
vessels is noted by the increased warmth and redness of the area in which
relaxation takes place.
Recapitulation. - To recapitulate: (1) Capillary,
circulation is passive. (2) Vasoconstriction of the arterioles causes a
decrease in the lumen of the capillary. (3) Vasodilation of the arterioles
causes increase in the lumen of the capillary. (4) General vasoconstriction
of the cutaneous blood vessels slows the heart and causes it to work against
higher pressure, but the heart is relieved by relaxation of blood vessels
in visceral areas, chiefly the splanchnics. (5) Decrease of constrictor
effect on superficial vessels causes a more rapid heart beat, which is
quickly controlled by constriction in the splanchnic area. (6) The vasomotor
center in the medulla acts according to the sum of the sensory influences
reaching it from all parts of the body. (7) The spinal vasomotor centers
act according to the influences sent to them by the chief center and the
sensory impulses which enter their segment of the cord.
Vasomotor Centers. - The vasomotor centers
for the various viscera, organs and members are as follows:
HEAD: The superior cervical ganglion.
EYE: The superior cervical ganglion through the fifth
NOSE, THROAT, TONSILS, TONGUE and GUMS: By the same
path. Dilator fibers for the tongue per the lingual branch of the
fifth cranial nerve.
BRAIN: "Sherrington and others have demonstrated
the presence of vasomotor nerves in the vessels of the brain. It
is probable that the cerebral circulation is wholly dependent upon the
general blood pressure, and, inasmuch as the general blood pressure is
very markedly regulated by the capacious splanchnic area, it is obvious
that the cerebral circulation may be better controlled by modifying the
blood supply of the splanchnic area than by any attempts at the modification
of the cerebral circulation itself."
Sympathetic fibers to the anterior and middle fossae
come from the superior cervical ganglion per the carotid plexus.
Sympathetic fibers are distributed to the vessels in the posterior fossa
from the vertebral plexus which is formed by fibers from the inferior cervical
THYROID GLAND: Middle and inferior cervical ganglion.
The vasoconstrictors for the blood vessels of the
head, face and neck with their contained organs leave the spinal cord in
the upper dorsal, second to fifth, and pass thence through the cervical
LUNGS: Second to the sixth dorsal.
INTESTINES: The vasoconstrictors for the mesenteric
blood vessels are found in the splanchnic nerves. Commencing at the
fifth dorsal, there is a segmental distribution to the various portions
of the intestines. The lowest constrictor influence comes from the
second lumbar. Vasodilator fibers are also found in the splanchnics.
LIVER: Sixth to tenth dorsal, right side.
KIDNEY: Tenth to twelfth dorsal.
SPLEEN: Ninth, tenth and eleventh dorsal, left side.
The vagus is a motor nerve to the muscular fibers in the trabeculae of
PORTAL SYSTEM: Fifth to ninth dorsal.
EXTERNAL GENERATIVE ORGANS: First and second lumbar,
through the lumbar sympathetic ganglia, second to the fifth, to the hypogastric
plexus, thence through the pelvic plexuses and pudic nerves to the generative
organs. Function, vasoconstriction. First, second and third
sacral nerves are vasodilators to the same organs.
INTERNAL GENERATIVE ORGANS: Vasoconstrictor influence
at first and second lumbar.
ARTERIES TO THE SKIN OF THE BACK: Vasoconstrictor
influence from sympathetic ganglion of the corresponding segment.
UPPER EXTREMITY: Vasoconstrictor influence to the
skin, from second to the seventh dorsal.
LOWER EXTREMITY Sixth dorsal to second lumbar.
MUSCLES: Dilator influence to the arteries of the
muscles per motor nerves to the muscles.
Conclusions. - Vasomotor nerves are of two
classes, viz: Vasoconstrictor and vasodilator. These nerves act according
to the sum of the stimuli reaching their governing center over sensory
nerves of skin, muscle and gland. Therefore the osteopath depends
on increasing or decreasing the stimuli reaching the spinal centers.
The heart is innervated by two sets of nerves which
control it. These nerves arise from centers in the cerebrospinal
system and govern the action of the heart according to the sum of stimuli
reaching their centers over sensory nerves of skin, muscle and gland, and
in harmony with the resistance maintained by the peripheral blood vessels.
Since perivascular tissues are dependent on the transfusion
of nutriment from the blood, through the walls of the capillaries into
the lymph, and this process of transfusion is dependent on the tension
and speed of the current of blood in the capillaries, any condition which
markedly increases or decreases this speed and tension will affect the
nourishment of the tissues.
Hyperaemia. - A study of hyperaemia is, in
reality, a study of the vasomotor mechanism. We have noted the fact
of vasomotor nerves controlling the caliber of blood vessels. These
nerves are branches of the cerebrospinal system. Most of them leave
the spinal nerves and pass to the sympathetic spinal ganglia as rami-communicantes
and then pass up and down to other ganglia of the sympathetic system.
Some fibers return from the sympathetic to the spinal nerves and are distributed
to blood vessels of skin, muscle and bone in the area of distribution of
the spinal nerves. A few vasomotor nerves do not enter the sympathetic
system but pass directly to their destination with the spinal nerves.
Thus two paths exist by which vasomotor impulses reach the blood vessels,
a direct route with the spinal nerves and an indirect one through the sympathetics.
Experimenters have long noted the return of vascular
tone in an area whose vasoconstrictor nerves have been cut. This
return of vascular tonicity is supposed to be due to the presence of a
perivascular mechanism which is capable of acting feebly after all other
constrictor influences have been paralyzed.
So far as methods of treatment are concerned, we
have paid very little attention to the presence of vasodilator nerves,
but physiologists seem to prove that there are fibers leaving the cord
with the posterior roots of the nerve trunks which act as dilators when
irritated. The vasoconstrictor nerves are considered as constantly
Irritation of the dilator nerves or paralysis of
the constrictors will result in dilatation of the arterioles, so that the
capillaries will be dilated to their fullest extent. Such a condition
is called an "active hyperaemia." When the exit of the blood through the
veins is obstructed and congestion results it is denoted "passive hyperaemia."
The same irritants, mechanical, thermal and chemical,
which are capable of stimulating muscles to unusual or unequal contractions
so as to produce marked evidences of changed bony alignment, also cause
such decided changes in the caliber of blood vessels as, to cause tissues
to become hyperaemic or ischaemic.
If any hyperaemia exists in the mucosa of the stomach,
palpation around the sixth dorsal spine will disclose tenderness.
This spinal tenderness is probably due either to the irritation cif the
dilator fibers which accompany the posterior division of the fifth dorsal
nerve or to paralysis of the vasoconstrictors of that area. The resulting
dilatation impinges on sensory nerves and causes
tenderness. The irritation of sensory nerves in the mucosa of
the stomach causes dilatation of blood vessels in that area and in the
spinal area from which its sensory nerve, arise. The irritation might
have originated centrally and then involved the stomach, thus reversing
the course of the irritation. These reflex hyperaemias are continually
noted in practice, and it is through the reflexes that relief is obtained.
One of the classical experiments to prove the reflex action of vasomotor
nerves is to immerse one hand in cold water, the temperature of the other
hand will be lowered also.
It is quite generally conceded that the small arteries
and arterioles in all parts of the body are supplied with vasomotor nerves.
Their presence in the blood vessels of the brain has been recently proven
by G. C. Huber. is demonstration of vasomotor nerves in the cerebral blood
vessels explains many of the circulatory phenomena resulting from osteopathic
Irritation of sensory nerves in any part of the body
causes vascular dilatation in the irritated area. Physiological experiments
seem to prove that vasodilator fibers accompany the sensory nerves, or
that irritation of sensory nerves causes paralysis of vasoconstrictor nerves.
Irritation of the nerves of one side of the body by pricking with a pin
causes a rise of temperature on that side and a decrease on the unirritated
side, thus demonstrating that vasodilation follows sensory irritation.
Experiments to note the effects of direct mechanical
irritation of the stomach mucosa demonstrate that dilatation of gastric
blood vessels follows mechanical irritation. The physiological hyperaema
thus produced is for purposes of increased secretion. It is well
known that when this physiological congestion is continued without cessation,
as in the case when meals are frequent and full, the congestion becomes
pathological, and the secretion of mucus is rapid. The liver and
intestines become chronically congested from similar causes. This
hyperaemia leads to, exudates and hyperplasia which further irritates sensory
nerve endings and continues the dilatation of the arterioles. Thus
a vicious cycle of reflexes is established which tends to ever increasing
When the sensory nerve terminals in the stomach are
irritated and hyperaemia of the gastric vessels results, the influence
of the irritation does not end with gastric congestion, i. e., if the hyperaemia
be excessive, but causes dilatation of arteries in the spinal cord around
the roots of sensory nerves distributed in other parts of the body which
are supplied by branches of the same nerve trunk. The brain does
not always note the real location of the irritation. It may refer
the pain to any point supplied by a branch of the nerve trunk, one of whose
branches is irritated. Thus in the presence of chronic congestion
of the gastric mucosa, as in gastric catarrh, the irritation may not be
intense enough to impress the brain with a painful sensation, but a slight
increase of capillary pressure around the trunk of the sixth dorsal nerve
such as would be brought about by digital pressure made upon the muscles
around the sixth dorsal spine, would cause instant recognition of hyperaesthesia
by the patient. Continued pressure made around the spine drives the
blood out and lessens the sensitiveness. If hyperaemia has been intense
enough to cause exudates, pressure increases the pain the longer it is
continued, because the exudates have affected the venous circulation and
there is no open path for exit of the blood.
From personal experience I should judge that it is
quite probable that hyperaemia occurs along the whole course of the nerve
and the nervi nervorum are rendered more sensitive thereby. In case
of absolute neuritis, manipulation relieves the condition temporarily,
but the pain increases shortly after the treatment is given. This
shows that a condition exists which is much more difficult to change than
a reflex hyperaemia.
Continued hyperaemic conditions cause increased nutrition,
i. e., hyperplasia of connective tissue. Connective tissue seems
to be more readily formed than any of the higher grades of tissue.
This may explain the rapid stiffening of the spine in cases of visceral
The digital pressure test is an excellent method
of differentiating the intensity of an hyperaemia. Even in cases
of conscious pain in the gastric or intestinal areas, it is possible to
use this test. ln colic, deep pressure made gradually will give relief,.but
in cases of gastric ulcer or other inflammatory conditions, pressure aggravates
Therapeutics. - We now have before us an array
of physiological facts and it remains for us to indicate how we shall use
The osteopath treats the vasomotor nerves as though
there were no dilator fibers to be reckoned with. Practically, we
consider that the vasoconstrictors are continually acting to maintain the
"tone" of the blood vessels. Therefore, having only this one force
with which to reckon, we consider all dilatation as vasoconstrictor paralysis.
We noted the fact that the cutaneuos and visceral
blood vessels were supplied with vasoconstrictors and that vasoconstriction
in the superficial area was compensated for by dilatation in the deep area.
A large number of sensory impressions reaching the
vasomotor centers over the sensory nerves of the skin usually result in
vasoconstriction of cutaneous blood vessels, hence internal congestion.
Irritation of the sensory nerves in the skin may cause muscle under the
skin to contract, thus obstructing the circulation in the skin. Therefore,
our manipulations for vasomotor effects naturally divide themselves into
two classes. First, those which inhibit cutaneous reflexes; second,
those which relax muscle in order to remove obstructions. This division
is purely arbitrary on our part, but it serves to explain our work.
We purposely leave out of this discussion the thought that we may have
an osseous lesion causing our vasomotor disturbance. We divide the
spine into areas according to the predominating influence which issues
from it; thus, the suboccipital fossa is the first important area.
It has long been known that pressure applied to this area in a case of
congestive headache gives great relief. The good effects are not
lost when the pressure is removed. This proves that the effect of
the pressure is on the nerves of that area, and that they are in close
central connection with the vasomotor center in the medulla. This
center regulates the caliber of the arteries all over the body. It
has been stated that pressure at the basi-occiput retards the blood flow
to the brain, the pressure being on the vertebral arteries. We believe
a careful examination of the atlas will convince one that in the average
skeleton the groove for the vertebral artery is so deep and well protected
that pressure on the surface of the neck cannot affect the artery.
If our pressure effect is mechanical, why does the effect last so long?
The blood stream is as swift as an ocean greyhound, and would rush into
the partly filled vessel with its previous force just the moment the pressure
is removed. We can only explain the result by noting the fact that
a change has been made in the entire circulation. Downward pressure
on the carotids is also recommended to retard the blood flow to the head.
This seems impracticable since the pressure cannot help affecting the venous
return as well as the carotid stream. The best and most lasting effects
are always vasomotor.
It is a well recognized fact in the osteopathic profession
that pressure in the suboccipital triangles causes a lessened blood pressure
all over the body. This fact is made use of daily to lower the temperature
of the body in cases of fever. If pressure had a mechanical rather
than a nervous effect on the circulation, we could hope for no general
effect, such as we do secure. This procedure is called inhibiting
the vasomotor center. Why does it inhibit? A "vascular tone"
is normal in the body in order to keep the blood equally distributed.
This "vascular tone" is easily disturbed since it acts according to the
sum of the sensory impulses reaching the center in the medulla. Pressure
in the suboccipital triangles affects not only the sum of the stimuli reaching
the center, but, most important of all, affects the capillary circulation
in this area which is in close nervous and circulatory connection with
the medulla. Any external application, such as hot or cold water,
local anaesthetics or counterirritants must 'secure whatever internal change
may be manifested, by the effect these therapeutic procedures may have
on cutaneous nerves.
Pressure in the suboccipital triangles will relax
the structures forming those triangles, thus lessening the sensory impulses
entering the center from that source. The relaxed structures will
hold more blood, hence they will in a slight degree relieve congestion
of the center.
These triangles are the bilateral surface centers
in which we operate to cause dilatation of vessels in the skin of the trunk
and extremities. We inhibit vasoconstriction of surface arteries.
The next great constrictor area is the splanchnic,
sixth to eleventh dorsal. This and the preceding area are the two
points of vantage for the osteopath. Since the splanchnic nerves
control a system of blood vessels whose combined capacity is equal to the
entire amount of the blood in the body, we can quickly realize what it
to the general circulation to affect this area. In all cases of congestive
headaches, fever, hyperaemia of visceral organs, etc., we "inhibit the
splanchnics." Why? The reflexes between the skin of the back and
the muscles of the back are so intense that they cause vascular constriction
of the cutaneous arteries and contraction of the deep muscles of the back,
thus adding a mechanical obstruction to the circulation of the blood, in
an already constricted area. Is it not possible, yes, probable, that
this state of the surface tissue causes a congestion of the vasomotor centers
in the dorsal area of the cord, thus nullifying their control of the splanchnic
area? Such a condition might be brought about by cold. The
eating of indigestible food which remains a long time in the digestive
tract may also be a cause.
The facts are as we have stated them, we inhibit
over the splanchnic area to lessen the intensity of the reflexes in that
area, thereby allowing the centers to regain their control. Remember
that inhibition lessens the sensory impressions reaching a center and relaxes
muscle both directly and indirectly.
Case Illustrations. - An illustration of osteopathic
methods applied to hyperaemia is ;afforded by the following case: A gentleman
about fifty years of age was inspecting mines in the vicinity of Yuma,
Arizona. He was of plethoric habit and hence the heat of that locality
affected him quickly. About eight p.m., while in his tent preparing
to bathe in order to get some relief from the intense heat, he felt a wave
of weakness pass up his left side and almost instantly power of motion
on that side was lost. Paralysis did not extend to the face.
The gentleman was brought to Los Angeles and came under the best of medical
treatment. Electricity and massage were tried with fair success,
but the left arm and hand remained helpless and were carried in a sling.
The hand was badly swollen and would pit under pressure, thus showing a
marked degree of vasoconstrictor paralysis. The hand and arm had
been thoroughly massaged for two months before osteopathic treatment was
given. One hour's seance with the masseur would make a wonderful
change in the hand, but the oedematous condition returned in a few hours.
The fingers were bent into the palm, showing a marked tendency to a spastic
From the medical standpoint it was considered sufficient
for this case to have the local massage of the arm and hand, with administration
The osteopathic examination was made at the end of
two months of the treatment just outlined. Slight signs of paralysis
were noted at the angle of the mouth on the hemiplegic side. Examination
of the neck showed marked contraction of the deep cervical muscles the
left side, extending from the occiput to the fourth cervical vertebra.
Moderate digital pressure over these contracted muscles caused pain.
There was also some tenderness as low as cause. The intense contraction
and tenderness in the upper cervical region was noted as a secondary lesion
existing as a result of a blood clot. It was reasoned that if these
contracted muscles could be relaxed cerebral circulation would be equalized
and more rapid absorption of the clot made possible. The spinal tenderness
was brought about by the same law of irritation of sensory nerves we have
previously stated. There was a dilated condition of the arterioles
around the roots of the sensory nerves in the cord similar in character
to that which existed at the peripheral distribution of these nerves, especially
in the hand. There was decided wrist and elbow reflex, showing that
the subsidiary nerve cells in the cord were intact, but that either the
cerebral motor areas or some part of their connecting paths were injured.
The vascular tone of blood vessels in all other parts of the body was good,
showing that the chief vasomotor center in the medulla was acting.
Here was a case showing a perfect reflex in the arm but loss of ability
to will a motion; perfect
sensation and vasomotor paralysis.
Treatment was directed to securing relaxation of
the contracted cervical muscles and to breaking up adhesions in the shoulder
joint which had been allowed to stiffen. No treatment was given to
the hand or arm. The patient was instructed to straighten the bent
fingers with the well hand many times per day to overcome the spastic condition.
Vasomotor tone returned to the blood vessels of the hand in proportion
to the amount of cervical relaxation accomplished. At the end of
one month the hand was allowed to hang naturally, and scarcely any oedema
was noticeable. Muscular control and power have steadily increased.
Another illustration is afforded by the following
case: A gentleman suffering with inflammatory rheumatism in the second
toe of the right foot sought relief by means of osteopathic treatment.
He had used the salicylates in his previous attacks, but his stomach had
become intolerant of them. The toe was red and angry looking, throbbing
with pain and swollen to the size of the great toe.
Examination of the spine revealed tenderness between
the fifth lumbar and third sacral spines, also between the second and third
lumbar spines. Why should tenderness exist at these points?
The answer according to anatomy and physiology is that these spinal areas
mark the point of emergence from the spinal column of the anterior crural
and great sciatic nerves which are distributed to equal parts of the affected
toe; the sensory nerves being irritated by the deposit of faulty katabolic
products in the tissues of the toe as the result of a slow blood stream.
In this case the patient was caught out in the rain and got his feet wet.
The peripheral irritation of the sensory nerves caused dilatation of the
arterioles and capillaries. The blood vessels around the roots of
other sensory nerves which were branches of the same nerve trunks also
dilated in response to this irritation, i. e., hyperaemia in the spinal
cord was brought about at the point of origin of the anterior crural and
great sciatic nerves, hence the sensory nerves to the skin and muscles
of the back which are innervated from the same area of the cord as these
great nerve trunks will also be tender to increased tension such as that
secured by the digital pressure.
In a case such as this we do not desire to have the
deposit in the toe taken up until the eliminating organs of the body are
acting freely. To force it into the circulation before such time
as it can be eliminated may result in inflaming another part. It
is quite necessary that the throbbing pain be subdued so that sleep may
be had. The patient soon learns to take advantage of venous circulation
by elevating the foot. If pressure upon, and a gentle relaxing movement
of the muscles in the spinal area is made, there will quickly be noted
a decrease in spinal sensitiveness followed by lessened conscious pain
in the toe. It is quite probable that pain in the toe is due to hyperaemia;
sensitiveness in the spinal area is due to the same sort of condition,
the difference being in degree. It is impossible to prove the presence
of these transitory hyperaemias by any direct observations any more than
it is possible to prove by post mortem examination that hyperaemia or anaemia
of the brain is present as a fixed pathological lesion in faulty functioning
of the brain.
Pressure and relaxation in the spinal area draws
the blood away from its position around the nerve trunk roots and thus
stops many of the impulses which would originate centrally as a result
of the irritation of the sensory roots of the nerve trunk.
We usually think of these reflex sensitive areas
of the spine as being evidence of the ability of all the branches of a
nerve trunk to express some degree of the irritation being, brought to
bear on any one of the branches. It seems to me that in the light
of what is known to happen in the area of an irritated nerve, hyperemia,
that the same change in circulation may occur around the roots of its parent
nerve trunk and be the sole reason for what we denominate a reflex pain.
By giving the heavy movement required to replace a subluxated
vertebra or even to relax tense muscles around an otherwise normal articulation,
it is quite probable that inexplicable changes are wrought in the circulation
at these points which immediately change the character of the nerve impulses
originating or reflexing from this portion of the spinal cord.