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DIGESTIVE ORGANS (PATHOLOGY)
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See also:DIGESTIVE See also:ORGANS (See also:PATHOLOGY) . Several facts of importance have to be See also:borne in mind for a proper appreciation of the pathology of the organs concerned in digestive processes (for the See also:anatomy see ALIMENTARY See also:CANAL and allied articles). In the first See also:place, more than all other systems, the digestive comprises greater range of structure and exhibits wider diversity of See also:function within its domain. Each See also:separate structure and each different function presents See also:special pathological signs and symptoms. Again, the duties imposed upon the See also:system.have to be performed notwithstanding See also:constant See also:variations in the See also:work set them. The crude articles of See also:diet offered them vary immensely in nature, bulk and utility, from which they must elaborate See also:simple See also:food-elements for absorption, incorporate them after absorption into complex organic substances properly designed to See also:supply the constant needs of cellular activity, of growth and repair; and fitly harmonized to fulfil the many requirements of very divergent processes and functions. Any See also:form of unphysiological diet, each failure to cater for the wants of any special See also:tissue engaged in, or of any processes of, See also:metabolism, carry with them pathological signs. Perhaps in greater degree than elsewhere are the individual sections of the digestive system dependent upon, and closely correlated with, one another. The lungs can only yield See also:oxygen to the See also:blood when the oxygen is uncombined; no compounds are of use. The digestive organs have to See also:deal with an enormous variety of See also:compound bodies, from which to obtain the elements necessary for protoplasmic upkeep and activity. Morbid lesions of the See also:respiratory and circulatory systems are frequently capable of See also:compensation through increased activity elsewhere, and the symptoms they give rise to follow chiefly along one See also:line; diseases of the digestive organs are more liable to occasion disorders elsewhere than to excite compensatory actions. The digestive system includes every See also:organ, function and See also:process concerned with the utilization of food-stuffs, from the moment of their entrance into the mouth, their preparation in the canal, assimilation with the tissues, their employment therein, up to their See also:excretion or See also:expulsion in the form of See also:waste. Each portion resembles a See also:link of a continuous See also:chain; each link depends upon the integrity of the others, the weakening or breaking of one straining or making impotent the chain as a whole. The mucous membrane lining the alimentary See also:tract is the See also:part most subject to pathological alterations, and in this connexion it should be remembered that this membrane differs both in structure and functions throughout the tract. Chiefly protective from the mouth to the cardia, it is secretory and absorbent in the See also:stomach and bowel; while the glandular cells forming part of it secrete both See also:acid and alkaline fluids, several ferments or mucus. Over the dorsum of the See also:tongue its modified cells subserve the sense of See also:taste. Without, connected with it by the submucous connective tissue, is placed the See also:muscular coat, and externally over the greater portion of its length the peritoneal serous membrane. All parts are supplied with blood-vessels, See also:lymph-ducts and nerves, the last belonging either to See also:local or to central circuits. Associated with the tract are the salivary glands, the See also:liver and the See also:pancreas; while, in addition, lymphoid tissue is met with diffusely scattered throughout the lining membranes in the tonsils, appendix, solitary glands and Peyer's patches, and the mesenteric glands. The functions of the various parts of the system in whose lesions we are here interested are many in number, and can only be summarized here. (For the See also:physiology of digestion see See also:NUTRITION.) Broadly, they maybe given as: (I) Ingestion and swallowing of food, transmission of it through the tract, and expulsion of the waste material; (2) secretion of acids and alkalis for the performance of digestive processes, aided by (3) elaboration and addition of complex bodies, termed enzymes or ferments; (4) secretion of mucus; (5) See also:protection of the See also:body against organismal infection, and against toxic products; (6) absorption of food elements and reconstitution of them into complex substances fitted for metabolic application; and (q) excretion of the waste products of protoplasmic See also:action.. These 'junctions may oe aitered by disease, singly or in See also:conjunction; it is rare, however, to find but one affected, while an apparently identical disturbance of function may often arise from totally different organic lesions. Another point of importance is seen in the See also:close interdependence which exists between the secretions of acid and those of alkaline reaction. i he difference in reaction seems to See also:act mutatis mutandis as a stimulant in each instance. See also:General Diseases. In all sections of the alimentary canal actively engaged in the ligestion of food, a well-marked local engorgement of the blood-vessels supplying the walls occurs. The hyperaemia abates soon263 after completion of the special duties of the individual sections. This normal See also:condition ma,y be abnormally exaggerated by over-stimulation from irritant poisons introduced into the canal; from too See also:rich, too copious or indigestible Ivesbnsar articles of diet; or from too prolonged an experience of some unvaried See also:kind of food-stuff, especially if large quantities of it are necessary for metabolic needs; entering into the first See also:stage of inflammation, acute hyperaemia. More important, because productive of less tractable lesions, is passive congestion of the digestive organs. Whenever the flow of blood into the right See also:side of the See also:heart is hindered, whether it arise from disease of the heart itself, or of the lungs, or proceed from obstruction in some part of the portal system, the damming-back of the venous circulation speedily produces a more or less pronounced stasis of the blood in the walls of the alimentary canal and in the associated abdominal glands. The lack of a sufficiently vigorous flow of blood is followed by deficient secretion of digestive agents from the glandular elements involved, by decreased motility of the muscular coats of the stomach and bowel, and lessened adapt-ability throughout for dealing with even slight irregular demands on their See also:powers. The mucous membrane of the stomach and bowel, less able to withstand the effects of irritation, even of a See also:minor See also:character, readily passes into a condition of chronic See also:catarrh, while it frequently is the seat of small abrasions, haemorrhagic erosions, which may cause vomiting of blood and the See also:appearance of blood in the stools. Obstruction to the flow of blood from the liver leads to See also:dilatation of its blood-vessels, consequent pressure upon the hepatic cells adjoining them, and their See also:gradual loss of function, or even See also:atrophy and degeneration. In addition to the results of such passive congestion exhibited by the stomach and bowel as noted above, passive congestion of the liver is often accompanied by varicose enlargement of the abdominal See also:veins, in particular of those which surround the See also:lower end of the See also:oesophagus, the lowest part of the rectum and anus. In the latter position these dilated veins constitute what are known as See also:haemorrhoids or piles, See also:internal or See also:external as their site lies within or outside the anal See also:aperture. The mucous and serous membranes of the canal and the glandular elements of the associated organs are the parts most subject to inflammatory affections. Among the several sections of the digestive tract itself, the oesophagus and jejunum are singularly exempt from inflammatory processes; the See also:fauces, stomach, caecum and appendix, ileum, mouth and duodenum (including the opening of the See also:common bile-duct), are more commonly involved. Stomatitis, or inflammation of the mouth, has many predisposing factors, but it has now been
definitely determined that its exciting cause is always hint'
some form of micro-organism. Any condition favouring mnrory lesions. oral See also:sepsis, as carious See also:teeth, pyorrhoea alveolaris (a dis-
See also:charge of pus due to inflamed granulations See also:round carious teeth), granulations beneath thick crusts of See also:tartar, or an irritating tooth See also:plate, favours the growth of pyogenic organisms and hence of stomatitis. Many varieties of this disease have been described, but all are forms of " pyogenic " or " septic stomatitis." This in its mildest form is catarrhal or erythematous, and is attended only by slight swelling tenderness and salivation. In its next stage of acuteness it is known as " membranous," as a false membrane is produced somewhat resembling that due to See also:diphtheria, though caused by a staphylococcus only. A still more acute form is " ulcerative," which may go on to the formation of an See also:abscess beneath the tongue. See also:Scarlet See also:fever usually gives rise to a slight inflammation of the mouth followed by desquamation, but more rarely it is accompanied by a most severe oedematous stomatitis with glossitis and See also:tonsillitis. See also:Erysipelas on the See also:face may infect the mouth, and an acute stomatitis due to the diphtheria bacillus, Klebs-Loeffler bacillus, has been described. A distinct and very dangerous form of stomatitis in infants and See also:young See also:children is known as " aphthous stomatitis " or " See also:thrush." This is caused by the growth of Oidium albicans. It is always preceded by a gastro-See also:enteritis and dry mouth, and if this is not attended to, soon attracts See also:attention by the little See also: Also from disease of the See also:nose, the upper See also:jaw, See also:palate and teeth do not make proper progress in development. There is overgrowth of tonsils, and See also:adenoids, with resulting deafness, and the See also:child's See also:mental development suffers. An See also:ordinary " sore See also:throat " usually signifies acute catarrh of the fauces, and is of purely organismal origin, " catching See also:cold " being only a secondary ' and minor cause. In " relaxed throats " there is a chronic catarrhal See also:state of the lining membrane, with some passive congestion. The tonsils are peculiarly liable to catarrhal attacks, as might a priori be expected by See also:reason of their See also:Cerberus-like function with regard to bacterial intruders. Still, acute attacks of tonsillitis appear on See also:good See also:evidence to be more common among individuals predisposed constitutionally to rheumatic manifestations. Cases of acute tonsillitis may or may not go on to suppuration or See also:quinsy; in all there is See also:great congestion of the glands, increased mucus secretion, and often secondary involvement of the lymphatic glands of the See also:neck. Repeated acute attacks often See also:lead to chronic inflammation, in which the glands are enlarged, and often hypertrophied in the true sense of the See also:term. The oesophagus is the seat of inflammation but seldom. In infants and young children thrush due to Oidium albicans may spread from the mouth, and also a diphtheritic inflammation spreads from the fauces into the oesophagus. A catarrhal oesophagitis is rarely seen, but the commonest form is traumatic, due to the swallowing of boiling See also:water, corrosive or irritant substances, &c. A non-See also:malignant ulceration may result which later leads on to an oesophageal stricture. The See also:physical changes presented by the coats of the stomach and the See also:intestine, the subjects of catarrhal attacks, closely resemble one another, but differ symptomatic-ally. Acute catarrh of the stomach is associated with intense hyperaemia of its lining coats, with visible engorgement and swelling of the mucous membrane, and an excessive secretion of mucus. The formation of active gastric juice is arrested, digestion ceases, peristaltic movements are sluggish or absent, unless so over-stimulated that they act in a direction the See also:reverse of the normal, and induce expulsion of the gastric contents by vomiting. The gastric contents, in whatever degree of dilution or concentration they may have been ingested, when ejected are of See also:porridge-thick consistency, and often but slightly digested. Such conditions may succeed a severe alcoholic bout, be caused by irritant substances taken in by the mouth or arise from fermentative processes in the stomach contents themselves. Should the irritating material succeed in passing from the stomach into the bowel, similar physical signs are See also:present; but as the quickest path offered for the expulsion of the offending substances from the body is downwards, peristalsis is increased, the flow of fluid from the intestinal glands is larger in bulk, though of less potency as regards its normal actions, than in See also:health, and See also:diarrhoea, with removal of the irritant, follows. As a general See also:rule, the more marked the involvement of the large bowel_, the severer and more fluid is the resultant diarrhoea. Inflammation of the stomach may be due to See also:mechanical injury, thermal or chemical irritants or invasion by micro-organisms. Also all the symptoms of gastric catarrh may be brought on by any acute emotion. The commonest mechanical injury is that due to an excess of food, especially when following on a fast; poisons act as irritants, and also the weevils of See also:cheese and the larvae of See also:insects. Inflammatory affections of the caecum and its attached appendix vermiformis are very common, and give rise to several special symptoms and signs. Acute inflammatory See also:appendicitis appears to be increasing in frequency, and is associated by many with the See also:modern deterioration in the teeth. See also:Constipation certainly predisposes to it, and it appears to be more prevalent among medical men, commercial travellers, or any engaged in arduous callings, subjected to irregular meals, fatigue and exposure. A See also:foreign body is the exciting cause in many cases, though less commonly so than was formerly imagined. The inflammation in the appendix varies in intensity from a very slight catarrhal or simple form to an ulcerative variety, and much more rarely to the acute fulminating appendicitis in which See also:necrosis of the appendix with abscess formation occurs. It is always accompanied by more or less See also:peritonitis, which is protective in nature, shutting in the inflammatory process. Very similar symptomatically is the condition termed perityphlitis, doubtless in former days frequently due to the appendix, an acute or chronic inflammation of the walls of the caecum often leading to abscess formation outside the gut, with or without See also:direct communication with the canal. The See also:colon is subject to three See also:main forms of inflammation. In simple colitis the mucous membrane of the colon is intensely injected, See also:bright red in See also:colour, and secreting a thick mucus, but there is no accompanying ulceration. It is often found in association with some constitutional disease, as Bright's disease, and also with See also:cancer of the bowel. But when it has no association with other trouble it is probably bacterial in origin, the Bacillus enteritidis spirogenes having been isolated in many cases. The motions always contain large quantities of mucus and more or less blood. A second very severe form of inflammation of the colon is known as " membranous colitis," and this may be either dyspeptic, or secondary to other diseases. In this trouble membranes are passed per See also:alum, accompanied by a See also:pain so intense as often to cause fainting. In severe cases See also:complete tubular casts of the intestine have been found. Often the motions contain very little faecal See also:matter, but consist only of membranes, mucus and a little blood. A third form is that known as " ulcerative colitis." Any part of the large intestine may be affected, and the ulceration shows no special See also:distribution. In severe cases the muscular coat is exposed, and perforation may ensue. The number of ulcers varies from a few to many dozen, and in See also:size from a See also:pea to a five-See also:shilling piece. Like all chronic intestinal ulcers they show a tendency to become transverse. Chronic catarrhal affections of the stomach are very common, and often follow upon repeated aCute attacks. In them the connective tissue increases at the expense of the glandular elements; the mucous membrane becomes thickened and less active in function. Should the muscular coat be involved, the See also:elasticity and contractility of the organ suffer; peristaltic See also:movement is weakened; expulsion of the contents through the pylorus hindered; and, aggravated by these effects, the condition becomes worse, atonic See also:dyspepsia in its most pronounced form results, with or without dilatation. Chronic vascular congestion may occasion in process of See also:time similar signs and symptoms. Duodenal catarrh is constantly associated with See also:jaundice, indeed is most probably the commonest cause of catarrhal jaundice; often it is accompanied by catarrh of the common bile-duct. Chronic inflammation of the small intestine gives rise to less prominent symptoms than in the stomach. It generally arises from more than one cause; or rather secondary causes rapidly become as import-See also:ant as the See also:primary in its incidence. Chronic congestion and See also:pro-longed irritation lead to deficient secretion and sluggish peristalsis; these effects encourage intestinal putrefaction and auto-See also:intoxication; and these latter, in turn, increase the local unrest. The intestinal mucous membrane, the peritoneum and the mesenteric glands are the See also:chief sites of tubercular infection in the digestive organs. Rarely met with in the gullet and stomach, and comparatively seldom in the mouth andl leslottsions. . lips, tubercular inflammation of the small intestine and peritoneum is common. Tubercular enteritis is a frequent See also:accompaniment of See also:phthisis, but may occur apart from tubercle of other organs. Children are especially subject to the primary form. Tubercular peritonitis often is present also. The inflammatory process readily tends towards See also:ulcer formation, with See also:haemorrhage and sometimes perforation. If in the large bowel, the symptoms are usually less acute than those characterizing tubercular inflammation of the small intestine. The appendix has been found to be the seat of tubercular processes; in the rectum they form the general cause of the fistulae and abscesses so commonly met with here. Tubercular peritonitis may be primary or secondary, acute or chronic; occasionally very acute cases are seen See also:running a rapid course; the See also:majority are chronic in type. The tubercles spread over the See also:surface of the serous membrane, and if small and not very numerous may give rise in chronic cases to few symptoms; if larger, and especially when they involve and obstruct the lymph- and blood-vessels, See also:ascites follows. It is hardly possible that tubercular invasion of the mesenteric glands can ever occur unaccompanied by peritoneal infection; but when the infection of the glands constitutes the most prominent sign, the term tabes mesenlerica is sometimes employed. Here the glands, enlarged, form a doughy See also:mass in the See also:abdomen, leading to marked protrusion of the abdominal walls, with wasting elsewhere and diarrhoea.
The liver is seldom attacked by tubercle, unless in cases of general miliary See also:tuberculosis. Now and then it contains large caseous tubercular masses in its substance.
An important fact with regard to the tubercular processes in the digestive organs lies in the ready response to treatment shown by many cases of peritoneal or mesenteric invasion, particularly in the young.
The later sequelae of syphilis display a predilection for the rectum and the liver, usually leading to the development of a stricture in the former, to a diffuse hepatitis or the formation of gummata in the second. In inherited syphilis the temporary teeth usually appear See also:early, are discoloured and soon crumble away. The permanent teeth may be See also:sound and healthy, but are often—especially the upper incisors—notched and stunted, when they are known as " See also:Hutchinson's teeth." As the result both of syphilis and of tubercle, the tissues of the liver and bowel may present a See also:peculiar alteration; they become amyloid, or lardaceous, a condition in which they appear " waxy," are coloured dark See also:mahogany See also: Diarrhoea, of a special " pea-soup " type, may or may not be present; while haemorrhage from the bowel, if ulcers have formed, is common. As the ulcers frequently extend down to the peritoneal coat of the bowel, perforation of this membrane and extravasation into the peritoneal cavity is easily induced .by irritants introduced into or elaborated in the bowel, acting physically or by the excitation of hyper-peristalsis. True See also:Asiatic See also:cholera is due to the See also:comma-bacillus or spirillum of cholera, which is found in the See also:rice-water evacuations, in the contents of the intestine after See also:death, and in the mucous membrane of the intestine just beneath the epithelium. It has not been found in the blood. It produces an intense irritation of the bowel, seldom of the stomach, without giving rise locally to any marked physical See also:change; it causes violent diarrhoea and copious discharges of " rice-water " stools, consisting largely of serum swarming with the organism. See also:Dysentery gives rise to an inflammation of the large intestine and sometimes of the lower part of the ileum, resulting in extensive ulceration and accompanied by faecal discharges of mucus, muco-pus or blood. In some forms a protozoan, the See also:Amoeba dysenteriae, is found in the stools—this is the amoebic dysentery; in other cases a bacillus, Bacillus dysenteriae, is found—the bacillary dysentery. Acute parotitis, or See also:mumps, is an infectious disease of the parotid glands, chiefly interesting because of the association between it and the testes in See also:males, inflammation of these glands occasionally following or replacing the See also:affection of the parotids. The causal agent is probably organismal, but has as yet escaped detection. The relative frequency with which malignant growths occur in the different organs of the digestive system may be gathered from the See also:tabular See also:analysis, on p. 266, of 1768 cases recorded in New growths. the books of the See also:Edinburgh Royal Infirmary as having been treated in the medical and surgical wards between the years 1892 and 1890 inclusive. Of these, 1263, or 71.44 %, were males; 505, or 28.56%, See also:females. (See Table I. p. 266.) If the figures there given be classified upon broader lines, the results are as given in Table II. p. 266, and speak for them-selves. The digestive organs are peculiarly subject to malignant disease, a result of the incessant changes from passive to active conditions, and See also:vice versa, called for by repeated introduction of food; while the See also:comparative frequency with which different parts are attacked depends, in part, upon the degree of irritation or changes of function imposed upon them. Scirrhous, encephaloid and colloid forms of carcinoma occur. In the stomach and oesophagus the scirrhous form is most common, the soft encephaloid form coming next. The most common situation for cancerous growth in the stomach is the pyloric region. See also:Walsh out of 1300 cases found 6o•8 % near the pylorus, 11.4 % over the lesser curvature, and 4.7 % more or less over the whole organ. The small intestine is rarely attacked by cancer; the large intestine frequently. The rectum, sigmoid flexure, caecum and colon are affected, and in this See also:order, the cylindrical-celled form being the most common. Carcinoma of the peritoneum is generally colloid in character, and is often secondary to growths in other organs. Cancer of the liver follows cancer of the stomach and rectum in frequency of occurrence, and is relatively more common in females than males. Secondary invasion of the liver is a frequent sequel to gastric cancer. The pancreas occasionally is the seat of cancerous growth. Sarcomata are not so often met with in the digestive organs. When present, they generally involve the peritoneum or the mesenteric glands.. The liver is sometimes attacked, the stomach rarely. Benign tumours are not of common occurrence in the digestive organs. Simple growths of the salivary glands, cysts of the pancreas and polypoid tumours of the rectum are the most frequent. The intestinal canal is the See also:habitat of the majority of See also:animal parasites found in See also:man. Frequently their presence leads to no morbid symptoms, local or general; nor are the symptoms, when they do arise, always characteristic of the presence of Animal parasites alone. See also:Discovery of their bodies, or of their pwwsit parasttes. eggs, in the stools is in most instances the only satis- factory See also:proof of their presence. The parasites found in the bowel belong principally to two natural See also:groups, See also:Protozoa and Metazoa. The great class of the Protozoa furnish amoebae, members of See also:Sporozoa and See also:Infusoria. The amoebae are almost invariably found in the large intestine; one See also:species, indeed, is termed Amoeba coli. The frequently observed relation between attacks of dysentery and the presence of amoebae in the stools has led to the proposition that an Amoeba dysenterica exists, causing the disease —a theory supported by the detection of amoebae in the contents of dysenteric abscesses of the liver. No symptoms of injury to health appear to accompany the presence of Sporozoa in the bowel, while the species of Infusoria found in it, the Cercomonas, and Trichomonas intestinalis, and the Balantidium coli, may or may not be guilty of prolonging conditions within the bowel as have previously set up diarrhoea. The Metazoa supply examples of intestinal parasites from the classes Annuloida and Nematoidea. To the former class belong the various See also:tapeworms found in the small intestine of man. They, like other intestinal parasites, are destitute of any See also:power of active digestion, simply absorbing the nutritious proceeds of the digestive processes of their hosts. Nematode See also:worms infest both the small and large intestine; Ascaris lumbricoides, the common round See also:worm, and the male Oxyuris vermicularis are found in the small bowel, the adult See also:female Oxyuris vermicularis and the Tricocephalus dis See also:par in the large. The eggs of the Trichina spiralis, when introduced with the food, develop in the bowel into larval forms which invade the tissues of the body, to find in the muscles congenial spots wherein to reach maturity. Similarly, the eggs of the Echinococcus are hatched in the bowel, and the embryos proceed to take up their See also:abode in the tissues of the body, developing into cysts capable of growth into mature worms after their ingestion by See also:dogs. Additional information and CommentsThere are no comments yet for this article.
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