356 DYNAMIC THEORY-DYSPEPSIA. tances, by certain attractive and repulsive forces; from whence it arises, that, in the volume of each body, there is much more void space than matter. On this system, the diversities in bodies may be explained, either by an essential difference in the atoms themselves, or by a difference in their form, size, position and distance. When two substances combine chemically, the atoms of one penetrate the interstices of the other, and the atoms of the two combine so intimately, that they become, in a manner, new sorts of constituent particles, excepting that they are not simple, but compound. DYNAMOMETER. Instruments for measuring the relative strength of men, and also of animals, are so called. DYSPEPSIA (SUOnetia, from dus, bad, and nes, digestion); difficulty of digestion. The strict etymology of the term implies an imperfect or disordered condition of the function of digestion. Systematic writers have been not a little perplexed to find an appropriate location for this affection in their artificial arrangements; and this difficulty must exist whilst symptoms, which are always fluctuating, are admitted, as the elements of nomenclature and arrangement, into systems of nosology. From the same circumstance, different symptoms of the affection have received the character of separate diseases, as apepsia, bradypepsia (Boadus, slow), anorexia, cardialgia, &c. These are no more than different grades in the symptoms, or varieties of the affection, and are not different diseases. The disorder of the digestive function is the most frequent and prevailing of the ailments that afflict man in the civilized state; all classes and all ages suffer from its attacks. Few are so happy as to pass through a life of ordinary duration, without undergoing a protracted struggle with this malady, and experiencing its torments. Once let it be fully established, and the comfort of existence disappears, or is regained, in most cases, tediously, and at the price of the most ascetic self-denial. The greater prevalence of dyspepsia or indigestion, in modern times, arises from the more frequent injury done to the stomach and its functions, directly, by the habits of luxurious indulgence, which have been exceedingly increased and extended; and, indirectly, by the multiplication of intellectual and moral agitations, from the extension of the commercial and financial operations of society, the greater activity and employment of the intellectual faculties, and augmentation of political, social and individ ual reverses. Something, too, is to be ascribed to the mere change of names. We call that dyspepsia now, which, formerly, was termed liver disease, bilious disorder, &c. A large proportion of the discomfort produced by this malady, arises from an ignorance of the digestive functions, leading to their abuse and premature derangement, and may be obviated, to a great extent, by instruction as to the nature of these functions, and their natural exercise. A general view of the digestive organs and functions is, therefore, requisite to an understanding of their disorders, the means to prevent, and the methods to remedy them. All organized or animated beings hold their existence under the condition of renewing, incessantly, the elements of their composition, by the appropriation to themselves of exterior matters. The simple animals (polypi, &c.) find, in the medium in which they live, and from which they directly receive them, the principles serving for their composition. The decomposition of animal and vegetable matter in the soil prepares the aliment or nutritive principle of vegetables, which, being held in solution by water, is absorbed by their roots. In all these beings there are no digestive organs or functions. The preparation of their nutriment is effected by physical operations exterior to themselves, and over which they have no control. In the higher or complete animals, or in man, the case is very different. Nature does not present to them the nutritive elements in a state fitted to be introduced, at once, into the interior organism, and to be employed in its composition. Their aliment consists of the nutritive principles in a compound state, intimately combined with other substances, from which they require to be disengaged. This is accomplished by the animal itself, which is provided with especial organs or apparatus and functions for this purpose. Digestion, then, consists in the disengagement of the nutritive elements from their combinations, and their reduction to the molecular state, admitting their introduction into the vessels, and their diffusion throughout the organism, for the purposes of its composition. It is a process analogous to the decomposition of the aliment of vegetables in the soil, and is effected, like all decompositions, by analogous or chemical operations. In this class, the procuring of the aliment is the act of the animal, depending on its voluntary powers, and is controlled by a great variety of circumstances, affecting the quantity and quality DYSPEPSIA. of the food. The organs composing the digestive apparatus in man are numerous. They are the mouth, arined with teeth, for mechanically breaking down the food by mastication; the salivary glands, furnishing a fluid intimately combined with the food, in mastication, and collected in the stomach, which is its reservoir; the pharynx, a muscular and membranous bag, for the reception of the masticated bolus from the mouth; the esophagus, a muscular and membranous tube, for conducting the bolus into the stomach; the stomach, a muscular and membranous bag, or enlargement of the alimentary canal, secreting a fluid or fluids, and a reservoir of the salivary and other secretory fluids of the interior surfaces, and in which the food is subjected to the decomposing process, until reduced to a pulpy inass, called chyme, consisting of the nutritive and innutritive elements, in a state of mechanical mixture; the duodenum, or second stomach, in which the chymous mass is submitted to the action of the biliary and pancreatic fluids, and in which the nutritive elements begin to separate from the innutritive matters, and to be absorbed by the lacteals, the roots of the animal economy; the liver and pancreas, furnishing bile and a species of saliva, which are mixed with, and act on, the chyme in the duodenum; the jejunum and ileum, or small intestines, in the course of which the separation, begun in the duodenum, is completed, and nearly the whole of the nutritive principles forming chyle are absorbed; and, lastly, the large intestines, a reservoir for all the excrementi tious principles, and which, in it, are converted into fæces. The whole of these organs compose the apparatus of digestion, but all are not of equal importance. The stomach and duodenum are the most eminent organs, and those whose condition exercises the greatest influence over the powers of digestion. of digestion. This apparatus is intimately connected, and a natural state of each of its parts, and a due exercise of the function of each, are essential to the healthy, undisturbed performance of digestion. This connexion is maintained through the ganglionary system of nerves, which not only unites these organs to gether, but combines them with all their congeries, appropriated to the perfect elab oration of the nutritive and sustaining principles of the economy. The stomach is the centre of the digestive apparatus, and may be regarded in nearly the same view, for the whole of the organs connected with individual nutrition. It owes 357 this character to its intimate union with 'the great solar plexus, the centre or brain, if it may be so termed, of the ganglionary system, regulating the nutritive functions. It is also immediately associated with the brain, through the medium of the eighth pair or pneumo-gastric nerves, and thus is placed in relation with the exercise of the moral and intellectual faculties. The stomach is consequently exposed to be disordered in its functions by violent inpressions from these faculties, as they arc also liable to be affected by the disordered conditions of the stomach. It is necessary to have these diversified connexions pointed out, to possess a clear understanding of the numerous and very different sources from which disturbances reach the process of digestion. A few words will now be necessary as to digestion itself. It is not all substances that are fitted for aliment, and are susceptible of digestion. Food is intended for the renovation of the body. It must consist of the same elements as the animal structure, and be capable of becoming organized and living. It must then contain, at least, three elementary animal principles-hydrogen, carbon and oxygen; and much of it contains, also, a fourth-azote. These elements form secondary compounds, in which state alone they constitute aliment: such are albumen, fibrin, gelatin, osmazome, oil, engan, farina, mucilage, and other animal and vegetable compounds. In all these substances, the molecules are easily separable without being chemically decomposed, which is one of the primary requisites of digestibility, and to effect which is the chief object of digestion. The masticated and insalivated food passes into the stomach. Here it is macerated in the saliva collected in the stomach, and in the proper liquid secreted by the villi of the gastric mucous membrane, at a temperature of 104° Fahr. This liquor is called gastric juice. Its true nature is not accurately determined, but, as far as examination has ascertained, it resembles saliva mixed with a small portion of lactic or muriatic acid. The stomach, in a healthy state, always contracts on its contents, so that its parietes, in digestion, are always in contact with the food. During digestion, the stomach has a constant vermicular motion, its muscular fibres contracting, successively, from the smaller to the larger end. The food is thus agitated, acquires a rotatory movement, and is mingled with the fluids of the stomach. In a short time, the change accomplished in the stomach commences; it becomes pulpy, and then reduced to a semifluid of a light, grayish color. From the uniform pressure of the stomach, the solid and most resisting portions are forced into the centre, while the digested and more fluid matter is found on the surface, and is gradually carried, by the contraction of the muscular fibres, into the duodenum. W. Philips and others have been led to suppose, from this circumstance, that the food in contact with the parietes of the stomach was alone digested; but it is a mere physical result, as uniform pressure in every direction, on a mass of different consistency, will always drive the most fluid to the circumference. The pulpy, grayish substance resulting from the stomachic digestion is called chyme. (q. v.) When examined with the microscope, the writer of this article has always found it to consist of an immense number of transparent globules, of various sizes, intermixed with undissolved fragments of the fibres of the alimentary substance. When food is masticated, and macerated for a few hours in simple saliva, he has found it to present exactly the same appearances as the chyme of the stomach. The digestion of the stomach, he infers from his experiments, is not a decomposition of the alimentary matter, but is a simple disintegration or reduction of it into its component molecules, the animal character remaining unchanged. The chyme, having passed into the duodenum, meets with the pancreatic liquor and the bile. What are the positive changes induced by these fluids, certainly is not accurately known. The acids of the chymous mass are neutralized by the alkaline principles of the bile, the picromel and coloring matter of which appear to coalesce with the unassimilable principles of the food, and assist in their conversion into faces. A chemical modification in some of the alimentary elements may also be effected. It is certain that chyle, or the nutritive principles of which blood is formed, does not appear in the lacteals until after the action of the bile and pancreatic fluid on the chyme, the product of the stomachic digestion. The action of the stomach on the food is that usually designated as digestion, and it is the derangement of this process that is usually expressed by the term dyspepsia. The process accomplished in the duodenum is also a true digestion, and the symptoms arising from its disordered state are confounded with those of the stomachic digestion, in the general accounts of dyspepsia. From this sketch From this sketch of the function of digestion, it is evident, that its most important agents are, 1st, the secreted fluids collected in the stomach; 2d, the contractile movements of the stomach, keeping the alimentary mass in constant agitation, mixing it with the fluids as they are secreted, and removing the portion digested or reduced into chyme; 3d, the application of the biliary and pancreatic fluids to the chyme in the duodenum; and, 4th, the contractile movements of this viscus. Most of the derangements of the digestive functions may be traced immediately to a departure from a natural state of some one or more of the above requisites of digestion. But this deviation from the natural order is, itself, an effect. The secretions are products of organs, and all excitement of the secretory organ, beyond the range of healthy action, causes vitiation of the secretion, or its total suspension. The action of the organ, diminished below the physiological range, is attended with other vitiations of the fluid, or the cessation of its secretion. Indigestion or dyspepsia is a consequence of both these conditions of the organs furnishing the fluids of digestion. Digestion is a very stimulating process. All functional actions are exciting. The increased demand for secreted fluids renders an augmented action, and increase of blood in the furnishing organ, necessary for their production. The presence of the food, drinks, &c., in the stomach, add to the stimulation of digestion. If the stomach of an animal be examined in the act of digestion, the mucous membrane is found of a diffused scarlet color. The movements of the stomach essential to digestion depend on its nervous communications, and especially on the integrity of the eighth pair of nerves. When these are divided, the stomach and oesophagus are paralysed; the food is no longer agitated and mixed up with the digestive fluids, and it often regurgitates from the stomach into the oesophagus. This experiment proves the influence of the contractile motion of the stomach in the act of digestion. The ganglionic nerves are not less important, though their specific influence cannot as readily be determined. cases of disease of these ganglions, vomiting, eructations, pain in the gastric region, and impaired digestion, are accompanying symptoms. Through the nervous system, the function of digestion is exposed to numerous disorders from moral impressions, especially those of an agitating character. From the preceding principles, it is evident that dyspepsia or indigestion is But in many DYSPEPSIA. not, properly speaking, a disease, but rather a symptom, attached to diseases of the apparatus of digestion, of very various and even opposite character. No specific treatment can, therefore, be laid down for the cure of dyspepsia, but each case requires to be managed according to its peculiar cause and nature. The organ of the digestive apparatus the most frequently productive of dyspeptic symptoms is the stomach, and the most usual cause of dyspepsia is its irritation and inflammation. The stomach is more liable than any other organ to these states, from its direct exposure to so many irritating aggressions, and its intimate sympathetic communications, which make it participate in the irritations of almost every other organ. The sub-acute and chronic forms of gastric irritation and inflammation, the signs of which have only of late been fully appreciated, are the disorders that, in seven or eight cases out of ten, are termed dyspepsia. Hence dyspepsia so frequently succeeds to febrile diseases, especially when treated by emetics, drastics, and the improper use of tonics and stimulants, which, although the patient escapes the fever, leave him a martyr to the chronic, disorganizing and perturbating irritations of the gastric mucous membrane. Hence, too, dyspepsia almost inevitably follows continued abuse of the digestive functions, from too highly seasoned or too abundant food, and stimulant drinks. The constant stimulation of the stomach finally becomes pathological or morbid. The simple prolongation of the functional excitement essential to digestion, continued from meal to meal, without permitting the stomach to revert to a state of repose, is sufficient to constitute a morbid state. All functions, for their perfect performance, require alternate periods of repose and activity. Incessant action irritates, inflames, and finally disorganizes the structure of the organs. A second condition of the stomach, productive of dyspepsia, is the congestion of its mucous tissue. This may be confined to the stomach alone, succeeding to an attack of acute gastritis, or following on its protracted irritation; or it may be an attendant on a general congestion of the whole portal system involving most of the abdominal viscera. Every irritation is attended with an afflux of the circulating fluids into the structure where it is seated, proportioned to its intensity and the vasoularity of the structure. This gorged state often continues after the subsidence of the irritation that provoked it, and pre 359 vents the resumption of the healthy functions. It is a state of passive congestion, and often exists in the mucous membrane of the stomach, after attacks of inflammation or acute irritation, and embarrasses its digestive operations. In all the extensive irritations of the alimentary canal, especially when attended with fever, having a paroxysmal character, the great portal system of the abdomen becomes loaded with blood, and congestion of its radical vessels ensues. The functions of the viscera are then disordered, the secretions are defective, and indigestion, costiveness, and their attendant nervous affections, are the necessary consequences of this condition. A third state of the stomach, a cause of dyspeptic symptoms, is precisely the reverse of the preceding. Asthenia, or diminution of vitality and actions below the healthy degree, occasionally takes possession of the stomach. Its circulation is then deficient, its secreted fluids are defective in quantity or quality, its sensibility is impaired, and digestion is imperfect. It is not probable that gastric asthenia is ever primitive. It succeeds to previous irritation, and is often occasioned by irritation in other organs.-The preceding form a first class of dyspeptic diseases, which, depending entirely on the stomach, may be termed gastric dyspepsia. They present characters totally different, and require a very opposite treatment. This class embraces three species. A second class of dyspeptic diseases is connected with the duodenum and its functions. This viscus, similarly constituted to the stomach, is subject to the same morbid alterations. Its mucous membrane is the seat of irritation, in its various grades, and productive of its usual consequences augmented irritability, sensibility, perversion of secretions, vitiation of structure, and disorder of function. Duodenic irritation most commonly accompanies gastric irritation, and the symptoms of the two are blended together. It exists, however, in many instances, independently, and then manifests particular symptoms, which are often termed dyspepsia. It is, more especially, the chronic irritation of the duodenum, that passes for dyspepsia. It is not probable, that congestion, or asthenia, ever affect the duodenum exclusively to the detriment of its function. When these states prevail, it is in conjunction with similar conditions of the whole digestive apparatus. At least, we have no knowledge of these states limited to the duodenum. A third class of dyspeptic diseases de pend on the nervous organs, which furnish nerves to the digestive viscera. The ganglionic system of nerves, distributed on each side of the spine, from the head to the pelvis, transmits nerves to all the organs connected with the nutritive function. The stomach, especially, is largely supplied from the solar plexus, and it receives, likewise, numerous nervous filaments from the pneumo-gastric, placing it in connexion with the functions of relation. The offices of the ganglionic system are not ascertained with precision. It is, however, well determined, that diseases of the ganglions disorder the functions of the viscera to which they transmit nerves. Hence arises an order of dyspeptic symptoms, independent of any immediate affection of the stomach, but occasioned by disease in the great solar, or other neighboring plexus. The disorders of the digestive functions, from this cause, are various. The sensibility of the stomach is sometimes greatly increased, constituting gastralgia. At other times, the secreted fluids of the stomach are morbidly acid. The stomach appears, in other cases, to be partially paralysed, and the peristaltic movements necessary for the admixture of the food, and the gastric fluids, and the continuous passage of the chyme into the duodenum, are suspended. At the same time, considerable quantities of flatus collect in and distend the stomach, preventing its action on the food. Mechanical manipulation of the abdomen, and particularly of the epigastrium, after a meal, becomes a substitute for the natural motion of the stomach, expels the wind, and facilitates digestion, that would otherwise be laborious and painful.-Dyspepsia or indigestion, from this analysis of its modes of production, is scen not to be a disease of uniform character, and depending on an identical state of the digestive organs. It is attached, as a symptom, rather, to a variety of conditions, each of which requires to be managed in its appropriate mode. It is not possible that it can be remedied by any one general mode of treatment, or by any set of specific remedies. The most common causes of dyspepsia are excesses of various kinds, especially in the quantity of food caten. Most individuals, in this country, err in this respect. Meat at three meals, daily, can be borne only by the most robust frames, and by hard laborers. Persons of a sedentary life require less nutriment; the economy makes less demand on the stomach for supplies; and if it be compelled then to labor, it is at its own loss. Exercise, or the expenditure of the nutritive elements by the economy, and the quantity of food to be digested, must be proportioned to each other, for the preservation of health and the due vigor of digestion. This fundamental principle is laid down in an axiom by Hippocrates-Homo edens sanus esse non potest, nisi etiam laborat.-DE DIETA, Lib. I. Good cookery, by rendering food more digestible, is one preservative against dyspepsia. The food, by being rendered tender and pulpy, is reduced to chyme in a shorter period, with a smaller expenditure of the secreted fluids, and less excitement of the stomach, than when it is not properly concocted. The art of long and healthiful living will depend on a perfect system of cooking, and à rational mode of eating. The powers of the stomach differ, in individuals, as much as the force of their muscles; and each one must adopt a mode of nutrition, both as to quantity and quality of food, suitable to the wants of his economy and the digestive capacity of his stomach. The quality of food is a frequent cause of dyspepsia. Tough and badly dressed meats, and crude vegetables, are among the prominent causes of this affliction, as are also hot bread and cakes, heavy and fresh bread, and the daily use of hot coffee for breakfast. In enumerating the more common causes of dyspeptic symptoms, we ought not to omit the frequent exacerbations of the malevolent passions, as anger, hatred, envy, jealousy, and, what is not often suspected, excessive indulgence and abuses of the venereal propensity. pensity. Another fruitful source of the digestive disorders is found in the employment of emetics, and in a frequent resort to saline or drastic cathartic medicines. When a constipated habit prevails, it should always be overcome, if possible, by a laxative regimen, and the aids of purgatives be cautiously and rarely invoked. |