The Abdominal and Pelvic Brain
Byron Robinson, M. D.

 A complete nervous apparatus consists of nerve or ganglion cell (e. g. cerebrum), a conducting cord (e. g. spinal cord, peripheral nerve), a periphery (e. g. Touch corpuscle).

 "Defeated o'er and o'er but ne'er disgraces." -- From the London Times and placed on a monument to Lord Beaconsfield.

    The sympathetic system of nerves (nervus vasomotorius) has experienced a variety of names. Synonyms: The vasomotor nerve (nervus vasomotorius) (Benedict Stilling, 1840 - German anatomist and surgeon, 1810-1879).  The sympathetic nervous system (systema nervorum sympathicum).  The vegetative nervous system (systema nervorum vegetatorum).  The ganglionic nervous system (systema nervorum ganglionicum).  The nervous system of organic life (systema nervorum vitae organicae.) The nerve system of nutritive life (systema nervorum vitae nutritiae).  The great sympathetic nerve (nervus sympathicus magnus).  The intercostal nerves (nervus intercostalis, Thomas Willis, 1622-1674, English anatomist).  The great intercostal nerve (nervus intercostalis ma-nus).  The trisplanchnic nerve (nervus trisplanchnicus, Francois Chaussier, 1746-1828, French anatomist).  The ganglionic nerves (nervus gangliosus).  The visceral nervous system (systema nervorum visceralis).  The trunk nervous system (systema nervorum trunci) (Rumpf  nerven system, K. F. Burdach, German anatomist, 1776-1847).  Grand sympathetic.  Since this system of nerves rules the motion of the heart and blood-vessels I shall assume with Stilling that the most appropriate term is the vasomotor nerve (nervus vasomotorius).  The term "sympathetic" nerve is without signification and hence should be discarded for a term significant of function; therefore, nervus vasomotorius, since the blood carries nutrition to all organs, the term "nerves of nutritive life" is included in the term nervus vasomotorius.

The Vasomotor Nerve

(nervus vasomotorius) or unfortunately the meaningless term sympathetic nerve consists of: I, nerve ganglia, II, nerve cords, III, nerve plexuses.
    I. The nerve ganglia, for practical purposes, present three grand divisions, viz.: (1) the bilateral chain of trunk ganglia (trunci nervi sympathici) extending from the base of the skull (ganglion of Francois Ribes, 1800-1864 - French professor of hygiene in Mont Pieler) to the distal end of the coccyx or coccygeal ganglion. (2) Three great ganglionated plexuses or aggregations of ganglia known as (prevertebral plexuses) the prevertebral plexuses of the thorax, abdomen and pelvis. (3) Automatic visceral ganglia or peripheral ganglia located in relation with the thoracic, abdominal and pelvic viscera.  The ganglia composed of nerve cells receive, reorganize and emit nerve forces.  II. (Afferent and efferent apparatus.) The nerve cords composed of nerve fibers consist of conducting, communicating or distributing apparatus.  III.  The vasomotor nerve possesses peculiar ganglionated plexuses and nonganglionated plexuses.  The vasomotor nerve is connected to the spinal cord through the (a) rami communicantes; (b) nervi sacralia and (c) to the cerebrum by the vagi.


    The vasomotor nerves or nervus vasomotorius originate in the cerebrospinal.  The bilateral halves of the vasomotor nerves (sympathetic) anastomose at the proximal and distal ends in the medium plexuses, especially through the cardiac plexus, the abdominal brain and pelvic brain, thus solidly and compactly anastomosing, connecting all viscera into a balanced system.  The vasomotor or sympathetic nerves are practically the visceral branches of the spinal nerves.  At the origin of the visceral vessels from the aorta,  vasomotor ganglia as a rule exist according in size with that of the vessel, e. g., at the origin of the aorta from the heart is located the cardiac ganglia or plexus of Wrisberg (German anatomist [1739-1808], professor at Gottingen).  At the origin of the coeliac axis is located the abdominal brain.  At the origin of the common iliacs originally existed the pelvic brain.  As a rule large vasomotor or sympathetic ganglia are located at the origin of large visceral vessels from the aorta.
    The chief manifestation of the vasomotor nerve is that it is endowed with a peculiar rhythmical phenomenon.  The ganglia of the nervus vasomotorius alone possess rhythm. (Some advocate that muscle possesses inherent power of rhythm, however, so far it is found in muscle supplied by the sympathetic nerve, e. g., muscles of the various visceral tracts.)
    The vasomotor nerve is particularly connected to the cerebrum through the vagi (proximal end) and to the spinal cord by the sacral nerves (distal end).
    The vasomotor nerves may pass directly from the bilateral chain of ganglia to the viscera without passing through intervening ganglia or plexuses, viz.: (a) pharyngeal plexuses located at the bifurcation of the carotids; (b) the cardiac plexus - located at the origin of the aorta from the heart; (c) the coeliac plexus (abdominal brain) located at the origin of the coeliac axis from the aorta; (d) the pelvic plexus (pelvic brain) located originally at the bifurcation of the aorta.  These four great ganglionated nerve plexuses are located intermediary between the bilateral vasomotor ganglionic chain and the automatic visceral ganglion located in relation with the organs.  The vasomotor ganglia are originating centers for nerve fibers, hence there is no relation between the number of nerve fibers which enter (afferent) and the number of nerves which depart (efferent) from a ganglion.  The ganglia of the vasomotor nerve (composed of ganglion cells) may be viewed as nervous centers, i. e., receive, reorganize and emit nerve forces to which all the physiologic and pathologic phenomena of the viscera may be referred.  The three prominent systems or series of ganglia constituting the vasomotor nerve, for convenience of description and practical purposes, may be termed: (a) primary ganglia (the vasomotor bilateral chain).  They appear assomatic or segmental in location on the lateral borders of the vertebra; (b) secondary ganglia (the four great prevertebral plexuses).  They appear to be located in relation to major blood-vessels, ventral to the vertebra; (c) tertiary ganglia (automatic visceral ganglia).  They appear to be locate in relation to viscera; in or on visceral wall.     The vasomotor visceral plexuses differ as much in arrangement from the vasomotor bilateral chain as the latter does from the spinal cord.
    The prevertebral plexuses form a kind of fusion between the cerebrospinal and vasomotor nervous systems; also they solidly and compactly anastomose, unite the bilateral ganglionic vasomotor chain and the automatic visceral ganglia as well as fuse the lateral halves of the nervus vasomotorius.  The signification of the vagi nerves may be observed when it was noted that they assist in the formation of three of the four great prevertebral vasomotor plexuses (see a, b, c, above).
    There is a peculiar balanced relation between the vagi and vasomotor nerves.  In animals especially, but also in man, there is a tendency to fusion of the vagi and vasomotor nerves.  They act vicariously for each other.  The greater the dimensions of the vasomotor nerves the less the dimensions of the vagi and vice versa.  The vagi are practically visceral nerves supplying, viz.: larynx, lung, heart, gastrium, liver, pancrea.  The vasomotor plexuses differ essentially from nerve plexuses formed by the cerebrospinal nerves.  In cerebrospinal nerve plexuses the afferent and efferent nerves are identical, however the afferent and efferent cords may be differently combined previous to entrance and subsequent to the formation of the plexus.
    The efferent branches departing from the plexus are precisely the same as the afferent branches that entered it.  On the contrary, in the vasomotor nerve plexuses there is no relation in dimension, number and structure of the afferent and efferent nerves with each other and the vasomotor nerve plexus itself.  The mode of distribution of the cerebrospinal and vasomotor nerves differ.
    The cerebrospinal nerves practically follow blood vessels; however, they divide by acute angles and do not form plexiform sheaths around blood vessels.
    The vasomotor nerves are generally distributed in the plexiform network ensheathing vessels and entering with them into the parenchyma of viscera.  From the reason that the vasomotor nerves are distributed in a plexiform gangliated network intimately ensheathing vessels (especially arteries) continuously to their destination, i. e., to the viscera, it has long originated the idea that the nervus vasomotorius belongs exclusively to the vascular system (blood, lymph vessels).  This view was especially promulgated by Claude Bernard, a French physiologist in 1851 (1813-1873).  The vasomotor nerves accompany the arteries not the veins, the trunk of the vena porta forming the exception to the rule.  In this chapter of applied anatomy and physiology of the nervus vasomotorius abdominalis I shall mention essential features only for practical reasons.  I shall consider in order regardless of any exact system the following subjects: Chapter IV, truncus sympathicus; Chapter V, nervus plexus aorticus abdominalis; Chapter VI, nervus plexus interiliacus; Chapter VII, nervi tractus intestinalis; Chapter VIII, nervi tractus urinarius; Chapter IX, nervi tractus genitalis; Chapter X, nervi tractus vascularius; Chapter XI, nervi tractus lymphaticus; Chapter XII, the abdominal brain (cerebrum abdominale); Chapter XIII, pelvic brain (cerebrum pelvicum).
Fig. 3. A diagram of the nervus vasomotorius (sympathetic) from the proximal end (ganglion of Ribes) to the distal end (coccygeal ganglion of Luschka) presenting a lateral view of the truncus vasomotorius (lateral chain) and the three prevertebral ganglia (cardiac, coeliac and pelvic plexuses).  Observe the exit of the three cardiac nerves, the three abdominal splanchnics and the 3 (or more) pelvic splanchnics (after Flower).
Fig. 4 (Jacob Henle, 1809-1885).  Represents the abdominal brain, the lumbar lateral chain, the inferior mesenteric ganglion and the hypogastric.plexus; 2, abdominal brain; 3 great splanchnic; 4, small splanchnic; 5, superior mesenteric artery; 6, renal ganglion; 7, renal artery with its ganglionic plexus surrounding it; 8, superior mesenteric ganglion; 9, ramus communicans; 10, lumbar lateral chain; 11, inferior mesenteric artery surrounded by its plexus; 12, 13, sacroiliac point; 14, innominate vein; 15, innominate artery; 16, ramus communicans to inferior mesenteric ganglion; 17, ramus communicans; 18, lateral chain; 19, right renal artery; 20, splanchnic minor; 21 , renal ganglion; 22, splanchnic ganglion; 23, splanchnic major; 24 ad-renal; 25, ganglion phrenicum.

Fig. 5. 1, incised edge of diaphragm; 2, lower end of esophagus; 3, left half of stomach; 4, small intestine; 5, sigmoid flexure of the colon; 6, rectum; 7, bladder; 8, prostate; 9, lower end of left vagus; 10, lower end of right vagus; 11, solar plexus; 12, lower end of great splanchnic nerve; 13, lower end of lesser splanchnic nerve; 14, 14, two last thoracic ganglia; 15, the four lumbar vertebrae ; 16, 16, 17, 17, branches from the lumbar ganglia; 18, superior mesenteric plexus; 19; 21, 22, 23, aortic lumbar plexus; 20, inferior mesenteric plexus; 24, 24, sacral portion of the sympathetic; 25, 25, 26, 26, 27, 27, hypogastric plexus ; 28, 29, 30, tenth, eleventh and twelfth dorsal nerves; 31, 32, 33, 34, 35, 36, 37, 38, 39, lumbar and sacral nerves. (Sappey, 1810.)