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



"Youth's Lexicon has no such word as fail." - Bulwer.

"It is our hearers who inspire us." - Vinet.

    1.  Gastrointestinal secretion is a significant and important matter in animal life.  Gastrointestinal secretions are under the control of the sympathetic ganglia located in the walls of the digestive tract.  We designate those ganglia in general as the Billroth-Meissner plexuses (plexus myentericus internus) situated immediately beneath the gastrointestinal mucosa.  They rule secretion.  We cannot properly separate the submucous nerve plexus from the Auerbach's plexus (plexus myentericus externus) which rules muscular motion and is situated between the circular and longitudinal muscles of the gastrointestinal tract.  One nerve plexus is a complement of the other.  As secretion without motion is of little avail, and motion without secretion is equally futile, peristaltic motion is necessary to sweep onward the food to be attacked by fresh glandular secretion and to eliminate and drain the system from the debris of food.  The remnants of the gastrointestinal feast must be removed by peristaltic movements.
    Besides, secretion is doubtless enhanced by the massage muscular contractions.  The large degree of independence exercised by the sympathetic ganglia, especially at a long distance from the cerebrospinal center, is quite suggestive that there will be local as well as general gastrointestinal mucous secretion.  From the very construction and function of the digestive tract we may expect local labors in it.  At several localities new and different secretions are added to the onward moving food, so that local and general digestion and secretion must occur.  I repeat that secretion and digestion are both local and general in regard to the digestive tube.  Yet the whole nerve apparatus of the digestive tract is a delicately balanced matter both as regards muscular and secretary activity.   Let us call up matters that daily occur, but are not always interpreted.  For example, a person eats some cucumbers or other indigestible and fermentable substance.  At the time that the indigestible substance is eaten the bowels may be as regular as clockwork and the feces of semi-liquid character.  Ten hours after eating the indigestible substance, when the regular stool is to be evacuated, it will be observed that: (1) the stool is delayed, the desire for stool is checked;, (2) if forced evacuation be exercised, the stool will be hard and relatively dry, for want of secretion is manifest by distinctly formed and shaped feces.
    Now what is the cause of this disturbance?  The cause is unbalanced secretion due to reflex irritation.  The irritation is going on in the business portion of the digestive tract, i. e., in the small intestines.  The subject is conscious of this disturbance only by a little pain, colic and excessive peristalsis.  He, however, notices that an excess of gases is being formed and passed per rectum.  He may not sleep well, but recognizes an indefinable restlessness.  This irritation may be active enough to produce seminal emissions during sleep.  The irritation in the small intestines has unbalanced the mechanism of secretion, so that it is called away from the large intestine, causing excessive secretion in the small intestine, and hence the dry formed feces in the large.  It is very likely that the excessive, deficient or disproportionate secretions may occur in separate localities of the digestive tract, just as peristalsis of the tract may be a local matter.  We know from experiment that peristalsis may arise, continue and subside, limited to a short piece of intestine.

     Fig. 80.  Drawn from cross section of the pancreatic and binary duct.  The minute glands of Theile may be observed in the walls of the ducts.  These are the so-called glands of the hepatic duct.  The figure illustrates the vast domain of secretion.

    The view of local disturbance in both peristalsis and secretion sending out its reflex power and disturbing the whole digestive tract is in accord with pathologic data.  For example, a perforation of the appendix may so unbalance the nerve apparatus as to feel it at the umbilicus.  It is a reality.  The secretion of the gastrointestinal mucosa is entirely beyond the control of the will.  In secretions we are especially dealing with the sympathetic nerve, for secretions have a close relation to the size of the blood vessels.
    1.  All glands receive vessels.
    2.  All vessels have nerves to control their caliber.
    The gastric secretion may be reviewed in regard to experimental data.  The stomach is supplied with nerves for its muscles and for its glands, as motion and secretion are both necessary for normal digestion.  The Arrangement of the Auerbach and Billroth-Meissner plexuses is similar to the small intestines.  The splanchnic nerve is the chief vasomotor nerve, i. e., vasodilator and vasoconstrictor.   This is important, for secretion in general depends on the blood supply, as may be observed in location in the season of "rut," in glandular congestion.  But the gastric glands are ruled by the sympathetic nerves, whose chief origin exists in the abdominal brain.
    It must be claimed, however, that the stomach glands can act independently, from sympathetic influence alone, and also be changed or modified by the cerebrospinal.  It is doubtless true that there are not only vasomotor nerves in the spinal cord but that the abdominal brain is a great vasomotor center, in that the abdominal brain regulates the amount of blood to the gastric glands and consequently the amount, and to a certain degree the kind, of secretion of the stomach.  Yet there must be secretary nerves in the stomach which belong to the sympathetic.  Candor requires the statement that the full knowledge of the nerve supply of the gastric glands is not fully known.
    The independence of the sympathetic ganglia of the stomach is signified by the fact that the chief stimulus to the gastric secretion is food in the stomach.  It is asserted by some that stimulating any of the nerves going to the stomach does not influence the secretion, for it is found that secretion will go on under the stimulus of food when all the stomachic nerves are severed.  It is claimed, therefore, that the sympathetic ganglia in the stomachic walls are sufficient to act as centers for secretion.  This delegates large and significant powers to the sympathetic ganglia.
    The sympathetic ganglia are especially liable to reflex irritation, and nowhere is it more manifest than in the stomach.  The gastric secretion is modified by reflex stimuli from the brain, uterus, kidney. testicle, ovary, heart and spinal cord, etc., etc.  Emotions play a role in gastric secretion The successful treatment of stomachic disease is significant in methods of stimulating the stomach, as irritating its mucous wall, which not only starts secretion, but motion as well.  In ordinary stomach diseases there are four factors, viz.: (a) excessive secretion, (b ) deficient secretion, (c) disproportionate secretion, and (d) muscular motion.  Washing the stomach, irritating its wall with instruments or coarse food, will accomplish much in inducing health.  Doubtless this is the action of nux vomica and hot water.  The clinging germs should be washed from the dormant stomach wall and the muscular movements must be stirred to excite natural secretions.  It has astonished me at the frequent beneficial results of irrigation of the stomach.  It stirs to more normal rhythm the sympathetic ganglia, both of secretion and motion.  Besides, it washes from the stomach wall abnormal matter.  The stomach must have rest and repose or it cannot long stand irregular irritation without

     Fig. 81.  Presents the tunica mucosa, muscularis and serosa of the ureter, with several nerve ganglia located between the tunica serosa and muscularis.

resentment of the little circulation insults.  Hence the distal irritation from a diseased uterus, oviducts and ovaries sooner or later unbalances stomach function by its regular passage of the traumatic insults to the abdominal brain where reorganization occurs, perhaps with multiplication of effects.  The excitation of the diseased genitals has no season of rest, no day or night repose, but at any or all times it rushes and flashes, now tumultuous or turbulent, now pell mell and explosive.  There is nothing like a chronic atrophic myometritic uterus to derange and unbalance the gastric secretion and motion.
    The stomach is very highly supplied with blood-vessels and nerves, because it is a vast and complicated laboratory, requiring much energy to hold its delicate but active processes in the balanced order.  From experimental data we may view the stomachic glands as under the control of the sympathetic nerves, i. e., the ganglia in them.