THE PHYSIOLOGY OF THE ABDOMINAL AND PELVIC BRAIN
WITH AUTOMATIC VISCERAL GANGLIA.
The sympathetic nerve which rules visceral rhythm never sleeps. Visceral rhythm
(peristalsis) and life are beyond the control of the will.
A Precedent is the terror of second rate men." - Dr. Joseph Parker.
The physiology of the abdominal and pelvic brain
with automatic visceral ganglia comprehends the real physiology of the
sympathetic, as the chief portion of the former is included or counted
in the latter. It may be asked, "What is understood by the physiology
of the sympathetic nerve?" We understand by the physiology of any organ
the use it yields to the economy, or the purpose it subserves to the animal.
It may be stated in the beginning that it is difficult to definitely and
exactly define the physiology of the sympathetic nerves, as they are often
largely mingled with those of the cerebrospinal system. The cerebrospinal
and sympathetic systems of nerves have a certain initial dependence on
each other, like the individuals of well ordered society. Yet certain
limited liberties are assumed by both systems. The Federal government
presides as a central power over the various states, but the latter assume
many independent liberties of action. The states act and execute
independently of the central government. So it is in the human body,
an exquisitely perfect product of millions of ages; the sympathetic nerve,
though dependent for much of its power on the cerebrospinal axis, has in
its influence over circulation and the abdominal viscera a certain independence
The sympathetic is not merely an agent of the brain
and cord. It generates action itself. It is, in general, a
nerve center characterized by the power to receive sensation and send out
motion., It has all the elements of any nervous system, viz.: a ganglion
cell, a conducting cord, and a periphery. It is not attempted here
to argue that either the cerebrospinal axis or the sympathetic nerve is
absolutely independent of the other. The fact is that each nerve
system has its own special duties. Both systems must be associated
in order to carry on life's functions and purposes. It may be said
that man and woman are independent of each other; but their association
is required for the perfection of reproduction. In another place
I have arranged quite a number of propositions to show that the sympathetic
nerve enjoys a large degree of independence. In the discussion of
its physiology certain topics must be discussed, in order to better comprehend
the limits and factors of the field.
1. The abdominal pelvic brain, i. e., reorganizing
2. A very important factor will be the vaso-motor
nerves (i. e., vaso-constrictors and vaso-dilators).
3. The automatic visceral ganglia.
4. Glandular secretions (bile, urine, gastrointestinal
juices, milk, ova and semen).
6. Trophic nerves.
8. Reflex fibers.
The above nine divisions mark out a field for consideration.
It may be broadly stated that all healthy movements initiated and sustained
by the sympathetic nerves are involuntary movements.
The vaso-motor nerves. They are divided into vaso-constrictors
and vaso-dilators, and to Claude Bernard belongs the credit of first conclusively
showing (in 1851) that they exerted an influence over the caliber of the
vessels. Authors agree, in general, that here are vaso-motor centers
located in the spinal cord which control the caliber of vessels.
Some place the vaso-motor centers in the vascular columns of Clark.
Still another set of authors of great respectability claim that vaso-motor
centers are located along the peripheral nerve branches. Doubtless
there are in the walls of vessels nerve cells which are in connection with
the vaso-motor nerves. These vascular ganglia, or nerve cells send
fibers to the muscularis of the vessel, dilating or contracting it according
to the nature of the despatched stimulus.
It is not yet definitely settled whether the vaso-motor
nerves are constrictors or dilators, or whether there are distinct constrictors
and dilators. Some assert that there is a constrictor nerve only
and that dilation of the vessel is paresis of the constrictor. Later
authority seems to point to a vaso-dilator and vaso-constrictor, and the
fact that there are vaso-motor centers located on the vessel or adjacent
to it. It is evident to observers and clinicians that local variation
of circulation occurs in the genital or digestive tracts from reflex irritation.
By slight irritation one can produce a white line (vaso-constriction) and
by more severe irritation one can produce a red line (vaso-dilation).
Cold first constricts the vessels, but it is rapidly followed by vaso-dilation,
a redness. Now, this local variation of circulation occurs doubtless
with more distinctness in the visceral organs which are so highly supplied
with vaso-motor nerves, and so closely situated to the gigantic vaso-motor
center, the abdominal brain. The significance of vasoconstricting
nerves becomes very evident when it is recognized that they are so powerful
that they can drive or squeeze all the blood out of a part.
In death from peritonitis the vaso-constrictors
drive first all the blood out of the skin or periphery. The blood
is forced into the large arteries and veins by the effect of the vaso-constrictors
on the peripheral and smaller vessels. The vaso-dilators may be so
effectively exercised that the blood escapes through the wall of the blood-vessels
as in hemorrhagic peritonitis.
The vaso-motor nerves are of the sympathetic and
exercise control over the caliber of vessels. The controlling of
the lumen of vessels constitutes a vast field of physiology, in the domain
of the sympathetic. It constitutes vascular tone. Section of
the sympathetic dilates the vessels beyond the normal. One of the
chief offices of the sympathetic nerve is to preserve tone of vessels.
The nerves that insure tone in vessels issue from the sympathetic.
They are always active and never in repose, - a characteristic of the sympathetic
nerve. They pass to the muscular coat of the vessels and act as their
permanent guardian, in preserving permanent vascular tone. Variation
in this tone constitutes incipient disease. Doubtless the vascular
tone is the result of a reflex matter, and the factor in the reflection
is the blood-wave, i. e., the trauma or irritation of the blood-wave on
the endothelial membrane of the vessel induces the vaso-constrictors to
act permanently in preserving vascular tone. Congestion is only the
abolition of vascular tone. Goltz's percussion experiment demonstrates
the reflex nature of the action of vaso-motor nerves, as by tapping
on the exposed viscera he could produce dilatation of their vessels.
Hence in this case the centers for reflex action must lie in the
walls of the vessels themselves.
For a reflex act in the vaso-motor field, there
must exist several factors, as (a) muscular walls or contractile tissue;
(b) centripetal fibers; (c) a center of reflection; (d) centrifugal fibers.
All these factors exist on and adjacent to vessels.
For the reflex centers of vaso-motor movements we
may look to the cardiac ganglia, the abdominal brain or, especially, to
the ganglia around the vessels or in their walls. Finally, we may
claim that the vaso-motor nerves control the caliber of vessels, that they
belong to the sympathetic and that those of the abdominal viscera are chiefly
under the control of the gigantic vaso-motor center - the abdominal brain.
First, we must consider the abdominal brain, the
semilunar ganglia or solar plexus, in the physiology of the sympathetic.
This large ganglion receives sensation and sends out motion. It is
situated at the root of the great visceral artery i. e., at the foot of
the celiac axis. It lies behind the stomach and entwines itself about
the aorta and root of the celiac axis and superior mesenteric artery.
In short, it is located at the roots of the celiac, renal and superior
mesenteric arteries. It supplies all the abdominal viscera.
It is a gigantic vaso-motor center for the viscera, as is shown by its
location at the roots of the celiac, renal and superior mesenteric arteries
- the great abdominal visceral blood way. It is connected with almost
every organ in the body, with a supremacy over visceral circulation, with
a control over visceral secretion and nutrition, with a reflex influence
over the heart that often leads to fainting and may even lead to fatality.
It rules visceral rhythm. No wonder that we may consider the abdominal
brain the center of life itself, as the cranial brain is the center of
mental and Psychical forces!
The abdominal brain, or solar plexus, is composed
of the aggregation of coalescence of a large number of ganglia. On
the two sides of the abdominal brain are situated the semilunar ganglia
- compact masses of nerve cells, nerve cords and connective tissue.
During many dissections I have noted that the right semilunar ganglion
is the smaller, doubtless because it lies behind the inferior vena cava,
and hence has suffered from pressure atrophy. Each of the semilunar
ganglia receives the great splanchnic nerve of the corresponding side.
The other splanchnics may enter it, but it is more to enter the abdominal
brain. It may be here stated that although the semilunar ganglia
are located on the sides, they are practically so intimately associated
with the solar plexus that we insist in combining all the names into one,
viz.: that of Abdominal Brain.
All plexuses or strands of nerves are secondary.
The significance of the abdominal brain in the visceral physiology, i.
e., in life, may be compared to that of the sun over the planets.
The influence of the sun rules the planets, though they are influenced
by other suns and planets (e. g., the cerebrospinal). The abdominal
brain has ganglion cells (brain centers), nerve strands (nerve conductors)
and a peripheral nerve apparatus, just as the cranial brain possesses a
central, conducting and peripheral apparatus. The abdominal brain
can live without the cranial (shown by living fetuses with no trace of
cerebrospinal axis), while the cranial brain and the cord cannot live without
the abdominal brain.
The great sympathetic ganglia, of which the abdominal
brain is the ruling potentate, is the center of life itself. So long
as the forces of life, assimilation, circulation, respiration and secretion
proceed undisturbed, as in health, the abdominal brain remains a silent,
steady, but ceaseless worker; but being unbalanced by peripheral or central
irritation, it quickly manifests or resents the insult. From the
abdominal brain large plexuses with numerous nerve strands pass to every
abdominal viscus, connecting the viscera into a delicately balanced, nicely
ordered, exquisitely, arranged apparatus for the object of maintaining
life. The nerve plexuses or strands are arranged along the highways
of nourishment - blood and lymph vessels, and vary in size according to
the importance of the viscus supplied.
Laignel and Lasvastine, in their experiments upon dogs, have
found that ablation of the solar plexus is a serious operation; though traumatism
of the plexus even may cause death. They have called the solar syndrome
of paralysis the sum of symptoms produced by ablation of the plexus; it may
be superacute, acute, subacute, or chronic. The first form they have found
to be present in peritonitis, clinically, the second in lead colic; the others
in mucomembranous colitis. Certain affections, therefore, may be attributed
solely to disturbance of the solar plexus, and not to general systemic derangement.