The Abdominal and Pelvic Brain
Byron Robinson, M. D.
ABDOMINAL BRAIN - CEREBRUM ABDOMINALE
(A) ANATOMY; (B) PHYSIOLOGY.
0, gentle sleep, Nature's soft nurse.
- Shakespeare (1564-1616).
Embrooded was he, as it were a mede,
All full of freshe floures white and rede;
Singing he was, or floyting all the day;
He was as freshe as is the moneth of May.
- Description of the Squire in Geoffrey Chaucer
The abdominal brain or ganglion coeliacum has experienced
multiple names during the past three centuries.
Synonyms. - Celiac ganglion (ganglion coeliacum);
solar plexus (plexus solaris, Todd and Bowman, 1847); semilunar ganglion
(ganglion semilunare); the great abdominal ganglion (ganglion abdominale
maximum); abdominal brain (cerebrum abdominale, Wrisberg, 1780 [1739-1808]);
the nervous center of Willis (centrum nervosum Willisii, 1622-1675); epigastric
nervous center (centrum nervosum epigastricum); splanchnic ganglion (ganglion
splanchnicum); vascular abdominal brain (cerebrum abdominale vasculare);
epigastric plexus (plexus epigastricus); celiac plexus (plexus cceliacum).
Some authors have viewed the abdominal brain or
celiac ganglion as composed of two parts, right and left, bilateral and
paired. I shall consider it as practically one sympathetic ganglion
or plexus anatomically and physiologically, and term it the abdominal brain
- the celiac ganglion, a coalesced, vascular, visceral brain, unpaired,
existing at the origin of the celiac, superior mesenteric, and renal arteries
(major visceral arteries).
The arrangement of the abdominal brain consists
of: (a) afferent or centripetal nerves (entering or contributing nerves
from the cerebrum, spinal cord, or sympathetic); (b) efferent or centrifugal
nerves (distributing or visceral). The afferent nerves enter chiefly
on the proximal and lateral borders, while the efferent nerves radiate
from all regions of the abdominal brain - hence solar plexus. There
is no relation between the number and dimension of afferent and efferent
nerves of the abdominal brain.
(a) Afferent nerves. The afferent
or contributing nerves composing the abdominal brain are: (sympathetic),
(1) plexus aorticus thoracicus (unpaired); (2) nervus splanchnicus (paired),
constituting the most essential portion of the abdominal brain; (3) branches
from the two proximal lumbar ganglia (paired): (cerebrospinal) I, nervus
vagus (paired), especially the right; 11, nervus phrenicus (paired), especially
the right. The abdominal brain consists of the coalesced termination
of the above (1, 2, 3, I, II) five nerve apparatus. The abdominal
brain is the major assembling center of the abdominal sympathetic.
(b) The efferent nerves. The
efferent, visceral, or distributing nerves of the abdominal brain of various
caliber radiate in a plexiform arterial sheath to every abdominal viscus,
viz., to the tractus intestinalis and its appendages: plexus hepaticus,
lienalis, gastricus, mesentericus superior, mesentericus inferior, heemorrhoidalis;
to the tractus urinarius: plexus suprarenalis, renalis, ureteris, vesicalis,
urethralis; to the tractus genitalis: plexus ovaricus, hypogastricus (pelvic
brain), plexus uterinus pudendalis vaginalis; to the tractus vascularis
and tractus lymphaticus. The abdominal brain emits plexiform nerves
and ganglia fixed in connective tissue sheaths which intimately encase
the vascular tubes. The nerves emitted from the abdominal brain are
gray or white in color, limited in diameter, plexiform in arrangement,
resist tension on account of the thick fibrous neurilemma, and ganglia
are liable to occur at their points of crossing or anastomosis. The
radiating, efferent nerves of the abdominal brain accompany the arteries
arranged in a plexiform sheath or network. They do not accompany
the veins - the trunk of the vena portae being the only exception.
I. Position: Holotopy (relation to general
The abdominal brain is located at the proximal end
of the abdominal cavity immediately distal to the diaphragm. It is
situated medially, extraperitoneally, and is practically bilaterally symmetrical.
II. Skeletopy (relation to osseous skeleton).
The abdominal brain corresponds to the level of the first lumbar vertebra,
on its ventral surface.
III. Syntopy (relation to adjacent organs).
The syntopic relations of the abdominal brain are
intimate and profound connections with vascular and visceral organs.
It surrounds the roots of the celiac, superior mesenteric, and renal arteries
like a collar or fenestrated sheath. It is located extraperitoneally,
on the ventral surface of the aorta and crura of the diaphragm. It
is situated immediately distal to the hiatus aorticus of the diaphragm.
It lies between the diaphragmatic and renal arteries. Right and left
it projects against the capsules of the adrenals. It is located between
the proximal renal poles. It lies partly dorsal to the corpus pancreaticus
and stomach. Its right half lies between the right crus of the diaphragm
and the vena cava. Practically the abdominal brain is lodged in the
space bounded bilaterally by the adrenals and proximal renal poles; proximally
by a line drawn transversely from the proximal point of one adrenal to
that of the other; distally by the renal arteries. The situation
of the abdominal brain is included within the space of origin of the celiac
and renal arteries - some two inches.
IV. Idiotopy (relation of component segments).
The component parts of the abdominal brain are from
proximal to distal end in order, viz.: (a) The projecting ganglia of the
origin of the diaphragmatic nerves located on the proximal border - conical
elevations or bulb of the brain itself; (b) the semilunar ganglia, the
essential material in form and dimension of the abdominal brain, constituting
its major central segment; (c) the renal ganglia, located generally at
the origin of the renal arteries, are practically constant, however varying
in location, form, and dimension. The segments proximodistally are
compactly and solidly united by ganglionic masses, flattened commissures,
and nerve cords along the lateral borders of the aorta. The segments
laterally, i.e., the right half and left half, are united transversely
around the roots of the celiac, superior mesenteric, and renal arteries
by ganglionic arches, flattened commissures, and nerve cords extending
transversely from the right to left half of the brain.
Dimensions. - The abdominal brain or celiac
ganglion is the largest and richest ganglion of the sympathetic nerve.
Hence from a preponderating aggregation of nerve cells it becomes the ruling
potentate of the viscera. The left half is more compact, greater
in dorsoventral diameter, thicker, less fenestrated, and possesses more
definite regular borders than the right; however, the right half is greater
in surface area. Its diameters are: (a) transverse about 11/2 inches;
(b) proximodistal 1/4 inches; (c) dorsoventral about 1/6 inch. The
dimensions of the abdominal brain practically correspond with the space
bounded bilaterally by the two adrenals and the two proximal renal poles;
distally by the two renal arteries; proximally by the diaphragmatic arteries,
or a line drawn transversely from the proximal end of one adrenal to that
of the other. Its surface dimensions vary extremely on account of
the indefinite coalescence, interpolation, distribution, dislocation of
ganglion or by transportation along visceral vessels.
The Form. - The form of the abdominal brain
is variable; however, in general it is quadrilateral. It may present
a half-moon or horseshoe shape, or a ring surrounding the celiac axis and
superior mesenteric artery. It may also be represented by a single
broad fenestrated ganglionated plate which covers the ventral surface of
the aorta adjacent to the celiac axis, and occupies the space between the
adrenals and proximal renal poles. The left half may resemble a bean,
a retort in compact form, while the right half is more quadrilateral, flattened
(from compression of the vena cava), and irregular in contour. The
form has changed by development from coalescence, interpolation, isolation,
and transportation of ganglia along visceral vessels, the vertebral column
The Borders. - The borders of the abdominal
brain (margo cerebri abdominalis) are four, viz.: proximal, distal, and
two lateral. (a) The proximal border presents three factors of interest.
The first is the concave horseshoe-like depression made in it by the celiac
axis and the surrounding of the vessel like a collar by nerve cords and
ganglia in a connective tissue sheath. The other two factors are
the cone-like projections of a portion of the brain which emits bilaterally
the nervus (plexus) diaphragmaticus. The proximal border receives
the continuation of the nerves of plexus aorticus thoracalis as well as
the termination of the right vagus (cranial), and also communication may
occur with the right nervus phrenicus. The proximal border is generally
blunt and rounded. Practically the plexus Lyastricus is emitted from
its proximal border. (b) The lateral border (left) presents quite an uneven
line, with irregular projections for efferent nerves, chiefly destined
to the adrenals and kidneys, and for afferent nerves, especially the major
splanchnic. The main projections along its border are those produced
by the ganglion splanchnicum and ganglia renalia. (c) (right). The
lateral border is generally an irregular line caused by the irregular size
and location of the ganglion splanchnicum and ganglion adrenalis.
The lateral borders receive (afferent) nerves (splanchnic major) and emit
(efferent) nerves (plexus adrenalis and plexus renalis). (d) The
distal border is bounded by the arteria renalia - practically an even line.
it emits or distributes efferent nerves of various caliber to the abdominal
Fenestrae. - The compact left half of the
abdominal brain may be limitedly perforated, while the widely meshed right
half is considerably fenestrated with larger and smaller, irregular-shaped
apertures adding unevenness to the surface. The fenestrae possess
sloping, smooth, irregular contoured edges and are occupied with connective
tissue, blood and lymph vessels, glands, and areolar tissue. The
chief central fenestrae are produced by the celiac axis and superior mesenteric
artery. The left half of the brain generally has one major fenestra
due to a blood-vessel springing from the aorta. The right half of
the brain possesses some three definite apertures, large ones. In
general the right half possesses two kinds of fenestrae, viz.: (smaller)
those in the more solid median division of the brain, and (larger) those
in the lateral, more widely meshed portion. The splanchnic ganglia,
located at the termination of the splanchnic nerves, are situated in the
middle of the celiac plexus and represent the major ganglionic masses.
The Surfaces. - The surfaces of the
abdominal brain (facies cerebri abdominis) consist of two, viz.: (a) the
ventral, (b) the dorsal. The ventral surface is uneven, from coalescence
of smaller and larger ganglia, irregular coalescence, compression of adjacent
viscera (as the inferior vena cava), or dislocation of ganglia by transportation
along vessels. The ventral surface is convex from the dorsal compression
of the aorta and crura diaphragmatica. The ventral surface receives
(afferent) and emits (efferent) nerves; also may be observed nerve loops
which originate and insert themselves on the ventral surface. From
the ventral surface pass the nerves to the adrenal, pancreas, and plexus
renalis - in fact, the nerve plexuses accompanying the branches of the
celiac axis and many of the plexus rnesentericus superior from the ventral
surface. The surface is solidly bound by connective tissue to adjacent
structures. The ventral surface of the left half of the abdominal
brain is concave from the contact pressure of the cylindrical aorta and
The fenestrae or perforations of the dorsal surface
correspond with those of the ventral. Strong, fine white strands
of connective tissue, blood, nerves, and lymph vessels bind the dorsal
surface of tne abdominal brain solidly to the crura diaphragmatica, but
especially strong to the aortic. Nerves originate and depart from
the dorsal surface. From the dorsal surface nerves depart to the
aorta and diaphragm and the splanchnicus major, bilaterally, arrives on
the dorsal surface.
Ganglia. - There are usually six constant
ganglia in the abdominal brain, viz.: (a) Ganglia diaphragmatic (paired).
(b) ganglia splanchnica (paired); (c) ganglia renalia (paired). They
are solidly and compactly united into one anatomic and physiologic nerve
center - a brain. In general the ganglia do not agree in form or
dimension bilaterally. Practically the ganglia agree in position
bilaterally. However, the left semilunar ganglion is nearer the median
line than the right, and the left mainly lies on the aorta, while the right
chiefly rests on the crus of the diaphragm. The ganglia may rest
in an even transverse plane, or lie in superimposed layers in a dorsoventral
plane. The ganglia constituting the abdominal brain are as irregular
and variable as the plexus in which they are located. The ganglia
consist of large, swollen cords, or ganglionic arches or circles arranged
in a network. The dimension, form, and number of the ganglia may
vary from coalescence, isolation, interpolation, or transportation of ganglia
along vessels, bones, and muscles. The coalescence of the ganglia
may proceed to such an extent - that the abdominal brain will present the
appearance of several nodes, or the two semilunar ganglia may coalesce
and lie between the celiac and superior mesenteric arteries.
The ganglia may coalesce proximally and distally
in the form of a ganglionic ring surrounding the origin of the celiac and
mesenteric arteries. The ganglia of the abdominal brain may be flat
or elevated, single or multiple, united by gangliated commissures or flattened
nerve strands. The nervus splanchnicus major, the essential segment,
terminates bilaterally in the abdominal brain in a large semilunar or quadrilateral-shaped
nodule-ganglion splanchnicum (paired). The splanchnic ganglia may
assume the shape of the letter C. I have seen two splanchnic ganglia on
each side of almost equal dimensions formed by the splanchnic major and
1. The left semilunar ganglion has a more definite
border, is nearer to the median line, greater in dorsoventral diameter,
more compact, yet smaller and less fenestrated than the right. It
lies transversely on the side of the aorta between the renal and diaphragmatic
arteries. Its average diameters are: proximodistal, 1/2 inch; transverse,
1 inch; dorsoventral, 1/6 inch. Its thickest border is the left,
its thinnest is the right. Its ventral surface is uneven, convex;
the dorsal, concave. It is flask or quadrilateral in form.
The right proximal angle is elongated into a horn-like process to join
its opposite fellow. Afferent nerves arrive and efferent nerves depart
from all surfaces and borders except part of the left. Proximally,
it is connected with the diaphragmatic ganglion - externally with the splanchnic
nerve, medially with the opposite fellow (right half of brain).
2. The right semilunar ganglion is
more flattened, greater in surface area, more extensively fenestrated,
and less in dorsoventral diameter than the left. It lies between
the vena cava (ventral) and right crus of the diaphragm (dorsal); and between
the renal and diaphragmatic arteries. Afferent nerves arrive and
efferent nerves depart from its surfaces and borders. The left, proximal,
angle is prolonged into a horn-like process to join its opposite fellow.
Proximally it is connected with the diaphragmatic ganglion, distally with
the renal ganglion; externally with the splanchnic nerve; and medially
with the opposite fellow (left half of the brain).
Ganglion of the Phrenic Artery (Ganglion Arteria,
Phrenicae). - In this brief note I wish to present a sympathetic ganglion
(bilateral) which I have not found described in literature.
This ganglion consists of a constant pyramidal, or cone-shaped projection
on the proximal border of the abdominal brain in the course of the phrenic
In Fig. I on the right side it is located by a hook
at the figure 2 in the abdominal brain. On the left side it is located
between the splenic and phrenic artery.
The phrenic ganglion projects bulb-like from the
proximal border of the cerebrum abdominale similar to that of the olfactory
nerve from the cranial cerebrum. It is a part and parcel of it.
By a general observation in dissecting the sympathetic nerve (nervus vasomotorius)
it will be evident that sympathetic ganglia are located at the origin of
the vessels from the aorta, as at the foot of the celiac axis (ganglion
semilunare) at the origin of the renal artery (ganglion renale) at the
origin of the arteria mesenterica inferior (ganglion mesentericum inferius)
at the origin of the two common iliacs from the aorta (the interiliac nerve
disc), and so forth. Hence it is in accordance with this rule that
the ganglion arterix phrenicae is found in the course of the phrenic artery
(bilateral). If the phrenic artery has an anomalous origin and course
the phrenic ganglion tends to follow its origin and course, and it was
this anatomic relation that called my attention to this heretofore undescribed
constant ganglion. I do not refer to the diaphragmatic ganglion (ganglion
diaphragmaticum) located on the diaphragm on the right side (only) about
two inches from the abdominal brain. The abdominal brain consists
practically of three ganglia (bilateral). They are: 1. Ganglion semilunare
(bilateral), located on the middle part of the lateral border of the abdominal
brain at the termination of the major splanchnic nerve (Sp. in figures).
This ganglion is related to the origin of the celiac artery. 2. Ganglion
renale (bilateral), located at the distal lateral border of the abdominal
brain, and belongs to the origin of the arteria renalis. 3. Ganglion
arterioe phrenicae (bilateral), located at the proximal border of the abdominal
brain in the course of the phrenic artery.
In certain subjects the ganglion of the phrenic
artery is located exactly at the origin of the phrenic artery from the
aorta. However, the origin of the phrenic artery varies considerably,
and this alters to some extent the relations of the phrenic ganglion from
The phrenic ganglia are constant structures, constantly
located in relation to the course of the phrenic arteries so far as I can
determine by dissection. The importance of the abdominal brain, with
its ganglia, will sooner or later be realized by the general profession.
The diaphragmatic ganglia are practically bilaterally
symmetrical in location, form, and dimension. They project as pyramids
or cones from the proximal border of the semilunar ganglia, at the origin
of the diaphragmatic arteries, giving origin in the diaphragmatic nerve.
They project from the abdominal brain as the olfactory projects from the
cranial brain - being a part of it. The diaphragmatic nerve possesses
a small ganglion some 2 1/2 inches from its origin, and it anastomoses
with the right phrenic.
5 and 6. The primary renal ganglia are practically
bilaterally symmetrical in form, location, and dimension. Their location
is generally at the origin of the renal arteries.
I. The ganglia of uncertain dimension, location,
and form associated with the abdominal brain are: (a) The nervus splanchnicus
minor terminates bilaterally more distalward generally on the renal arteries;
(b) the ganglion suprarenale supernum, which I have occasionally found
chiefly on the right suprarenal nerves. The color of the abdominal
brain is grayish-red; the consistence is moderately dense, due to the presence
of abundant connective tissue; the composition consists of an aggregation
of nerve ganglia, ensconced in dense connective tissue, varying in dimension,
number, and form. Each ganglion is composed of oval-shaped nerve
cells of various form and dimension.
Relations. - The relations of the abdominal
brain well encased in fibrous and connective tissue consist in intimate
connection with the abdominal aorta at the origin of the celiac axis, superior
mesenteric and renal arteries. It has also intimate but less solid
connections with the vena cava and renal veins. It is a vascular
brain of the abdomen. The abdominal brain lies in the square formed
by the proximal renal poles with adrenals and the renal arteries.
It is in relation to the dorsal surface of the body of the pancreas, peritoneum,
and stomach. The abdominal brain in general occupies the space including
the origin of the major visceral arteries, viz.: (a) arteria coeliaca;
(b) arteria mesenterica superior; (c) arteria renalis - three mighty visceral
arteries originating from the aorta within the space of an inch and a half.
Hence practically the term abdominal brain should include the aggregated
or coalesced ganglia located at the origin of the major visceral vessels.
With development of viscera and elongation of visceral arteries, the ganglia
become isolated from the original abdominal brain and transported along
the vessels toward the viscera.
The two best examples are the renal and aortic arteries
with their numerous transported large ganglia - ganglia renalia and ganglia
aortica. Development has sometimes separated the cord and ganglion
of the nervus splanchnicus minor from the abdominal brain by placing it
more distalward and lateralward toward the region of the origin of the
arteria renalis, thus altering the form and contour of the abdominal brain.
The nerve plexuses and ganglia of the abdominal brain, firmly bound in
sheaths by strong white connective and elastic tissue, encase the visceral
vessels and accompany them to the viscera. The abdominal brain is
solidly and compactly anastomosed, connected by nerves of various caliber
with all the abdominal viscera, viz., tractus intestinalis, urinarius,
genitalis, vascularis, lymphaticus. It is evident from its location
at the origin of the celiac axis and superior mesenteric arteries that
the abdominal brain in its origin was a primitive brain for the tractus
vascularis. With development of viscera and elongation of visceral
arteries, dislocation, multiplication, distribution, coalescence or transportation,
of ganglia, other viscera have acquired local ganglionic rulers, e.g.,
the pelvic brain - ganglion cervicale. However, present conditions
allow the origin of the abdominal brain to remain at the exit of the major
visceral vessel. It should be denominated a vascular brain.
From the abdominal brain radiate plexuses of various caliber, chiefly
in vessels, to all the abdominal viscera, viz., tractus intestinalis, genitalis,
urinarius, vascularis, and lymphaticus. The abdominal brain emits
more nerves than it receives, and hence is a creating, producing center,
a source for new and increased nerves. Nerve reception occurs chiefly
at the proximal (plexus aorticus thoracalis, vagi) and lateral borders
(splanchnics, major, medius, minor). Nerve emission occurs mainly
at the distal (plexus aorticus abdominalis) and lateral borders (plexus
renalis, adrenalis). From the dorsal and ventral surface, from the
bilateral proximal and distal borders of the abdominal brain, nerves arrive
and depart. Bilaterally radiate the renal and adrenal nerves, and
arrive the splanchnicus; proximally radiate a few to the aorta, and arrives
the plexus aorticus thoracalis and vagi; dorsally many nerves pass to the
aorta and diaphragm, and arrive the branches from the splanchnics; ventrally
a number of nerves radiate to the adrenals and pancreas; distally are emitted
nerve plexuses of vast importance on visceral arteries of corresponding
I. Tractus intestinalis: (1) Plexus
coeliacus, emitting (a) plexus gastriticus accompanying the arteria gastrica;
(b) plexus hepaticus accompanying the arteria hepatica; (c) plexus lienalis
accompanying the arteria lienalis. (2) Plexus mesentericus superior accompanying
the arteria mesenterica superior (to the enteron - except the duodenum,
and colon, except the caecum, right colon and right half of transverse
colon). (3) Plexus mesentericus inferior accompanying the arteria mesenterica
inferior (to the left half of the transverse colon, left colon, sigmoid
flexure, and rectum).
II. Tractus urinarius: (1) Plexus
adrenalis accompanying the arteria adrenalis. (2) Plexus renalis accompanying
the arteria renalis. (3) Plexus ureteris accompanying: (a) rami arteriee
renales; (b) arteria ovarica; (c) arteria ureteris media (from common iliac);
(d) arteria uterina. (4) Plexus haemorrhoidalis accompanying the arteria
haemorrhoidalia. (5) Plexus hypogastricus accompanying the arteria
hypogastrica. (6) Pelvic brain (ganglion cervicale) emits nerves which
pass directly to the ureter without accompanying blood-vessels as well
as the plexus vesicalis. (7) Plexus vesicalis accompanying the arteria
vesicalis superior, media, and inferior (hemorrhoidal). (8) Plexus urethralis
(a continuation of the plexus vesicalis) accompanying arteria pudenda.
III. Tractus genitalis: (1) Plexus
aorticus accompanying the arteria aortica abdominis. (2) Plexus hypogastricus
(a continuation of the plexus aorticus) accompanying the arteria iliaca
communis and arteria hypogastrica. (3) Plexus ovaricus accompanying the
arteria ovarica. (4) Plexus arteriae uterinae, accompanying the arteria
uterina. (5) Cerebrum pelvicum (pelvic brain), which emits the plexus uterinus
without accompanying vessels as well as the plexus vaginalis. The
sympathetic nerve cords and ganglia accompanying vessels (blood, particularly
arteries and lymph) arranged as a network in a connective tissue sheath
which encases the vessel.
(B) PHYSIOLOGY OF THE ABDOMINAL BRAIN.
In mammals there exist two brains of almost equal
importance to the individual and race. One is the cranial brain,
the instrument of volitions of mental progress and physical protection.
The other is the abdominal brain, the instrument of vascular and visceral
function. It is the automatic, vegetative, the subconscious brain
of physical existence. In the cranial brain resides the consciousness
of right and wrong. Here is the seat of all progress, mental and
moral, and in it lies the instinct to protect life and the fear of death.
However, in the abdomen there exists a brain of wonderful power maintaining
eternal, restless vigilance over its viscera. It presides over organic
life. It dominates the rhythmical function of viscera. It is
an automatic nerve center, a physiologic and an anatomic brain. Being
located at the origin of the celiac, superior mesenteric. and renal arteries
- the major abdominal visceral arteries - it is a primary vascular brain
of the abdomen and a secondary brain for visceral rhythm. The abdominal
brain presides as the central potentate, over the physiology of the abdominal
viscera. The common functions of these viscera are rhythm, secretion,
and absorption, and to preside over this triple office is the chief duty
of the abdominal brain. To the common functions of the abdominal
viscera must be added tb especial functions of the tractus genitalis -
ovulation, menstruation, gestation; however, many of the functions of the
visceral tract are delegated to the subordinate local ruler - the pelvic
brain. The abdominal brain is a receiver, a reorganizer, an emitter
of nerve forces. It has the powers of a brain. It is a reflex
center in health and disease. The sympathetic abdominal nerve alone
possesses the power of rhythm. Every organ possesses rhythm.
In this rhythm of involuntary visceral muscles is doubtless included the
factors of initiation, maintenance, and conclusion of visceral absorption
and secretion. The rhythmic, peristaltic muscles massage the glands,
inciting their function of secretion and absorption.
The individual functions of the abdominal brain
are numerous and important, viz.: (1) It is the source of new nerves, as
it possesses more efferent than afferent nerves. (2) it demedullates nerves;
nerves enter sheathed and depart unsheathed. (3) It presides over the rhythm,
peristalsis, of visceral muscles. (4) It presides over the absorption and
secretion of visceral glands - e.g., the glands lining tubular viscera
- and those denominated glandular appendages. (5) The abdominal brain is
a giant vasomotor center, controlling the caliber of the abdominal vessels
(blood and lymph); it should be termed nervus vasomotorius. (6) It possesses
nutritive powers over the nerves passing from it to the periphery. (7)
It is the major abdominal reflex center.
The abdominal brain is not a mere agent of the brain
and cord; it receives and generates nerve forces itself; it presides over
nutrition. It is the center of life itself. In it are repeated
all the physiologic and pathologic manifestations of visceral function
(rhythm, absorption, secretion, and nutrition). The abdominal brain
can live without the cranial brain, which is demonstrated by living children
being born without cerebrospinal axis. On the contrary the cranial
brain can not live without the abdominal brain. The central idea
in the abdominal brain should entitle it, in my opinion, to the name vascular
or vasomotor brain of the abdomen (cerebrum vasculare abdominale).
It initiates, sustains, and concludes visceral rhythm (the peristalsis
of involuntary, visceral muscles) - e.g., in the tractus vascularis, intestinalis.
genitalis, and urinarius. It presides over the absorption and secretion
of the viscera - e. g., the mucous glands of the tubular viscera and visceral
glandular appendages. It is evident from the great volume of blood
occasionally found in the vastly distended abdominal veins at autopsy that
a subject could bleed to death in his own abdominal vessels. The
abdominal brain, the vascular cerebrum, is responsible for this condition,
having forgotten, from paralysis. to control the lumen of the vessels.
From the anatomic vascular connection it is impossible to extirpate the
abdominal brain from living animals, hence the reports of experimentation
accompanied with its extirpation are unreliable. The abdominal brain
is the nervous executive of the abdominal vessels and viscera, the duties
of which are to see that the functions of the viscera (rhythm, secretion,
and absorption) are faithfully executed. The abdominal brain assumes
practically an independent existence; however, the cerebrospinal axis asserts
a controlling influence over it. For example, in children whose cerebrospinal
axis is not completely developed, and at death of adults, when the
cerebrospinal axis has lost its complete control, the intestines will mutiny,
assuming a wild, disordered, violent peristalsis, resulting in intestinal
The utility of the abdominal brain in practice is
important - for example, in postpartum hemorrhage the older practitioners
taught that by compression of the aorta the hemorrhage was checked.
This, of course, is an error, as the technique, if it were possible to
execute, would not materially affect the bleeding, as ovarian blood-supply
would continue. The physiologic explanation of checking postpartum
hemorrhage by pressure over the abdominal aorta is that the manipulation
stimulates the plexus aorticus and plexus hypogastricus, which is transmitted
to the pelvic brain, where it is reorganized and transmitted over the plexus
uterinus to the myometrium, the elastic and muscular bundles of which being
excited, contract like living ligatures, checking the postpartum hemorrhage
by diminishing the lumen of the vessels. The irritation, pressure,
or trauma of the head of the child on the expanding cervix uteri during
the last month of gestation precipitates labor by its effect on the pelvic
brain (and consequently on the abdominal brain), by inducing vigorous,
persistent uterine contractions. In feeble labor pains, during uterine
inertia, vigorous uterine contractions may be excited by the finger per
rectum or per vaginam, irritating or massaging the pelvic brain.
The pelvic brain is palpated with facility, as it is located on the lateral
vaginal fornix. Again, the pelvic brain is subordinate to the abdominal
brain; however, the pelvic brain must be intact to allow physiologic orders
to pass from the abdominal brain through the pelvic brain to the uterus.
For example, during labor sudden cessation of uterine peristalsis may occur
- uterine inertia. The probable explanation is that as the head passes
through the pelvis it traumatizes the pelvic brain, producing temporary
paresis from pressure, and partially checks the uterine rhythm. With
the progress of labor the pelvic brain recovers and its dynamics resume.
The temporary paresis of the pelvic brain does not
produce complete paralysis, because a few of the nerves of the plexus hypogastricus
(directly from the abdominal brain) pass to the uterus without first entering
the pelvic brain. The abdominal brain rules the physiology of the
abdominal visceral tracts. The methods to utilize the physiology
of the abdominal brain in practice are varied. For example, the mammary
gland is connected to the abdominal brain by at least three distinct routes,
viz.: (a) via the nerve plexuses accompanying the arteria mammaria and
arteria subclavia, whence the route is direct to the abdominal brain; (b)
via the nerve plexuses accompanying the arteriae intercostales to the aorta
and its plexus, whence the route is direct to the abdominal brain; (c)
via the nerve plexuses accompanying the arteria epigastrica superior and
inferior to the common iliac, whence the route (plexus) continues on the
artery of the round ligament to the plexus uterina, whence the route is
direct to the pelvic brain or abdominal brain. Therefore, by stimulating
or irritating the nipple with light friction or massaging the mammary gland,
the abdominal brain is reached by the above three routes, and consequently
the uterus is induced to contract more frequently, and if the experiments
be not repeated too rapidly, the uterine contraction will be more vigorous.
Again, the uterus mav be incited to more frequent and vigorous contractions
by administering a tablespoonful of hot fluid, which first emits the stimulation
over the plexus gastricus to the abdominal brain, where it is reorganized
and sent directly to the plexus uterinus, which incites the uterus to increased
peristalsis. The reverse physiology of the influence of visceral
tumors or pregnant genitals stimulating the mammary gland (over the above
three routes) is evident. The tumor or fetus in the genitals rapidly
induces the mammary gland to manifest objective disturbances of dimension,
circulation, color, palpation, as well as sensory disturbances.
Practically the uterine nerves originate in the
abdominal brain and possess a relative independent existence. Children
are born, expelled, from the uterus after the death of the mother.
Hyrtl, the celebrated Viennese anatomist, reports that during a war with
Spain some bandits hanged a pregnant woman. After she had hung on
the gallows for four hours, and consequently was long dead, she gave birth
to a living child. I have observed the giant uterus of slaughtered
pregnant cows executing with wondrous precision its rhythm hours subsequent
to death and evacuation of uterine contents. If one will extirpate
an oviduct from a human and place it in warm normal salt solution, oviductal
rhythm may be maintained by physical stiinulus - e.g., tapping with the
scalpel - for some three-quarters of an hour. If one will chloroform
a dog to death and incise the abdominal wall, exposing the intestines,
in a room of 70 degrees, the intestines will perform their rhythm, on being
tapped with the scalpel, for an hour and a half. The large urinary
vesical apparatus of steers will perform rhythmical movements for half
a dozen hours after death in summer temperature.
The anatomic location and the physiologic function of the abdominal
brain dignify it into a basic factor in diagnosis from pain. For
example, practically all acute inflammatory pain (localized peritonitis,
visceral perforation) or violent visceral irritation (calculus, volvulus,
invagination, acute strangulation, obstruction) is first experienced in
the epigastric region - i.e., reorganization occurs in the abdominal brain.
This means that all visceral pain, irritation, is first transmitted to
the abdominal brain, where it is reorganized and emitted to the abdominal
viscera, diffusing the wild, disordered, violent peristalsis (colic) universally
in the abdomen, which prevents the localizing of the pain by the diagnostician.
With the progress of the disease the abdominal brain and associated nerve
apparatus become accustomed to the new experience and the pain becomes
intensified, localized on definite nerve plexuses, whence the pain, tenderness,
can be diagnosed by distinct circumscribed localization. The best
example of this view is appendicitis.
The abdominal brain is the seat of shock.
A blow over the epigastrium, violent trauma to the abdominal brain, may
cause immediate shock, collapse, or death. I performed an autopsy
on a subject where invagination of the uterus had killed the patient in
two and a half hours. Death was due to shock in the abdominal brain,
transmitted to it over the hypogastric plexus from the traumatized (invaginated)
CONCLUSIONS AS REGARDS THE ABDOMINAL BRAIN.
The abdominal brain is a nervous center - i.e., it
receives, reorganizes, and emits nerve forces.
The abdominal brain is the nervous executive for the common functions
of the abdominal viscera, as rhythm, absorption, and secretion.
The abdominal brain was originally in function and
location a vascular brain - cerebrum vasculare. Though complicated
functions have been added, yet it is still a primary vasomotor center controlling
the caliber of the blood-vessels and consequently the volume of blood to
viscera, which determines visceral function.
The abdominal brain is a reflex center in health
It is the major assembling center of the abdominal
The abdominal brain is the seat of shock.
A blow or trauma on it may cause shock, collapse, or death.
It is the automatic, vegetative, the subconscious
brain of physical existence. It is the center of life itself.
In the abdominal brain are repeated all the physiologic
and pathologic manifestations of visceral function - rhythm, absorption,
secretion, menstruation, gestation, ovulation.
The abdominal brain can live without the cranial
brain (and spinal cord), for children have been born alive with no cerebrospinal
axis. Children have been born alive hours after the mother was dead.
The abdominal brain may be the agent of valuable
therapeutics - e.g., in postpartum hemorrhage massage of the aortic plexus
will stimulate the abdominal brain to control the blood-vessels of the
uterus. Massage of the aortic plexus will stimulate the abdominal
brain to send blood to the viscera, enhancing rhythm, secretion, and absorption,
improving constipation and increasing visceral drainage.
The abdominal brain is the primary agent of rhythmic
visceral motion. A wide office of the physician is to maintain regular
visceral rhythm by means of rational therapeutics, as regular habits and
exercise, wholesome coarse food, ample fluids, and proper rest.
An illustration of the sympathetic nerve with abdominal brain. In
this specimen the ureters (calyces, pelvis, and ureter proper) were dilated
to the dimensions of an index -finger, the channel of the tractus urinarius
presenting no sphincters intact. This subject possessed a typical
abdominal brain (1 and 2) as well as a well-marked pelvic brain (B).
The ganglion hypogastricum (H) is well marked. This illustration
presents fairly well the abdominal sympathetic with their varied anastomoses.
The great ganglionic masses of the abdomen (1 and 2) and pelvis (B) are
evident. It presents a general outline of its nervous vasomotoritis.
I secured this specimen from an autopsy through the courtesy of Drs.
W. A. Evans and O'Byrne.
This illustration is drawn from a specimen I secured at an autopsy through
the courtesy of Drs. Evans and O'Byrne. The right kidney was
dislocated, resting on the right common iliac artery, with its pelvis
(P) and hilum facing ventralward. The adrenal (Ad.) remained in
situ. It was a congenital renal dislocation, and was accompanied with
congenital malformations in the sympathetic nerve, or nervus vasomotorius.
1 and 2 is the abdominal brain. It sends five branches to the adrenal
from the right half (2). Though the sympathetic system is malformed,
yet the principal rules as regards the sympathetic ganglia still prevail,
viz., ganglia exist at the origin of abdominal visceral vessels, e.g.,
3, at the origin of the inferior mesenteric artery; at the root of the
renal vessels, HP is no doubt the ganglion originally at the root of the
common iliacs (coalesced). In this specimen the right ureter was
5 inches in length, while the left was 11 1/2. This specimen demonstrates
that the abdominal brain is located at the origin of the renal, celiac,
and superior mesenteric vessels - i.e., it is a vascular brain (cerebrum
ABDOMINAL BRAIN (S.P.).
This illustration was drawn from a specimen I secured courtesy of Dr.
W. A. Evans. It is not a typical abominal brain, on account of the
peculiar method of emission of the adrenal nerves (C) 10 on the left side
and 14 on the right side. The right side represents duplicate renal
and spermatic arteries. This is a typical subject to demonstrate
the abdominal brain as a vascular brain (cerebrum vasculare or cerebrum
vasomotorius), as it is located at the origin of the abdominal visceral
vessels, vis., renal, celiac, and superior mesenteric arteries.
B, splanchnic major; H, splanchnic minor; D, renal ganglia. This
specimen presents what I term the swan’s-neck-shaped ureters (2).
Note ureteral valves (5 and 6) and dilated ureters. The bladder
and prostrate are hypertrophied. The ureters present a network of
nerves surrounding them. Observe the large renal ganglion on the
ventral surface of the renal artery at D.
ABDOMINAL BRAIN - CEREBRUM ABDOMINALE.
This illustration was drawn from a carefully dissected abdominal brain.
I dissected the tissue under alcohol. The relations and proportions
are those of life, being drawn by accurate measurements. 1 and 2, abdominal
brain. Observe the nerves which the adrenals receive: Sp, splanchnic
major; DG, ganglion diaphragmaticum; GR, renal ganglia; Ad, adrenals;
LS, lesser splanchnics; RA, arteria renalis; H, hepatic; G, gastric; and
Sp, splenic artery. The hook fixes the ganglion of the phrenic artery
which I term ganglion arteriae phrenicae.
This illustration drawn from a cadaver, illustrates the location, relation,
and radiating plexuses of the solar plexus, or abdominal brain (71 and
72), which is built around the major visceral arteries, the celiac (73,
74, 75), superior mesenteric (1 6), and renal (88) arteries; hence it
dominates the visceral function as to vascularity (blood and lymph), peristalsis,
absorption, and secretion. The clinical manifestations of the abdominal
brain are coextensive with that of the abdominal viscera. This ganglion
of the first magnitude presents radiating plexuses to all the abdominal
viscera, presenting an exquisitely balanced and poised nervous mechanism,
controlling vascularity (blood and lymph), peristalsis, absorption, and
secretion. 76 and 185, splanchnic major; ll0, 111, ganglia ovarica.
The body from which this dissection was drawn possessed wide, flat nerves,
as is noted by the majestic ganglion - the abdominal brain or cerebrum
vasoinotorius ; 69 is the left vagus.
GANGLION CELLS IN THE ABDOMINAL BRAIN.
Drawn from a microscopic section of the abdominal brain. Observe
that the cells lie in connective tissue nests, i. e., the ganglion cells
are ensconced in separate chambers of connective tissue. The prolongations
of the cells, i. e., the conducting cords, pass hither and yon, forming