Mesentery

“ At first the stomach and intestine form a straight tube, which is connected to the dorsum of the embryo by a dorsal mesentery and to the mid-ventral wall in front of the umbilicus by a ventral mesentery. Into the ventral mesentery the liver grows as diverticula from the duodenum, so that some of the mesentery remains as the falciform ligament of the liver and some as the lesser omentum. Into the dorsal mesentery the pancreas grows, also as diverticula, from the duodenum, while the spleen is developed from the mesoderm contained in the same fold. ”

“ When the saving of time is of great importance the large intestine may be freed as described above, a ligature put around the upper end of the jejunum, and the mesentery severed at its root, so that the entire mass of small intestine with its mesentery is removed for further separation from the mesentery outside of the body. ”

“ The mesenteric glands, which are situated between two layers of serous membrane (mesentery) that connects the small intestine with the spinal column, occasionally become diseased in childhood, and prevent the chyle 122 from passing to the thoracic duct. Children thus affected have a voracious appetite, and at the same time are becoming more and more emaciated. The disease is called mesenteric consumption.
254. The LIVER, a gland appended to the alimentary canal, is the largest organ in the system, and weighs about four pounds. ”

“ In its earlier stages the primitive common mesentery forms a membrane which carries the intestinal blood vessels between its two layers, surrounds the embryonic alimentary canal and attaches the same to the ventral aspect of the chorda dorsalis and aorta. This is the permanent condition in many of the lower vertebrates in which the intestinal tube is suspended by a simple dorsal mesentery, a condition which is repeated by the embryos of man and the higher vertebrates. ”

“ The gland becomes very intimately connected with the serous layers of the primitive dorsal mesentery. In order to clearly comprehend the adult serous relations it is necessary to make a distinction between two divisions or portions of the gland, based upon the altered relations of the primitive dorsal mesentery which result from the differentiation of the primitive simple intestinal tube into stomach and duodenum. ”

“ When peritoneal adhesions that cannot be easily torn are present it may be necessary to remove the intestines with mesentery attached.
After the removal of the intestines from the body they are opened by the intestinal shears, beginning either with the jejunum or the large intestine, the cut being made in the line of the mesenteric attachment. As the intestine is opened careful attention should be paid to the contents of each portion. It is very poor technique to dilate the intestine with water or to run water through it before it is opened. ”

“ A. very justly refers to the counteraction and irritation these medicines excite on the mucous membrane of the bowels, by which the excitement of the serous tissue or of the diseased viscus is removed. He remarks that drastic purgatives are sometimes inadmissible in ascites, when an affection of the liver or mesentery is its remote cause, and there is a tendency to a spontaneous diarrhœa, which even the mildest purgatives would increase. "In the case of the mesentery, such a mode of treating dropsy would speedily destroy the patient." ”

“ This passage to the right is accompanied by a throwing over of the duodenal loop to the right, so that the right side of its mesentery becomes pressed against the dorsal wall of the abdomen and obliterated. This accounts for the fact that the pancreas and duodenum are only covered by peritoneum on their anterior surfaces in man. The formation of the lesser sac is due to the turning over of the stomach to the right, with the result that a cave, known sometimes as the bursa omentalis, is formed behind it. ”

“ Chronic diseases of the heart and lungs, local disturbances of the circulation, and tumors or tubercles of the intestines or mesentery are additional causes.
Lesions. These embrace attenuation of the intestinal walls at Peyers’ patches, a dark, slaty discoloration of the mucosa, more or less congestion, an accumulation of fœtid mucus in the small intestines, of mucus and black baked fæcal matters in the large, and discoloration of the mesenteric glands. Inter-dependent diseases of the heart, lungs and liver are not uncommon. ”

“ Nor is the disease confined to the bowels, but the mesentery and peritoneum, lining the parietes of the abdomen, share in the affection, and the belly is tumefied and tense. The surface of the abdomen is often tender to the touch, and there is frequent deep-seated lancinating pain within its cavity. Should these symptoms not subside under proper treatment, a rapid increase of the emaciation ensues, and the evening accession of fever is more severe, and in some instances, towards the conclusion, the little patient becomes comatose. ”

“ The mesentery grew out with these folds, but the presence of adjacent organs, the disturbance due to the outgrowth of the liver, and the secondary relations brought about between different portions of the gut, as the out-growing loops invaded each other's localities, disturbed the primitive simplicity. ”

“ You can see, if I gather up twenty feet of this ruffle into a space of six inches, how the mesentery, with the intestines folded in the free edge, are held in the abdominal cavity. They are held loosely, and at the same time so that the intestines cannot be tied in knots or loops upon each other. In this way the ruffle flares out into the abdominal cavity. The intestines should stay in their place close up under the liver and stomach, but if pressure is brought to bear around the body at this point, the bowels begin to sag into the abdominal cavity. ”

“ Inflammation of the peritonæum is known by pain all over the abdomen, which is increased on erecting the body. It has probably most frequently a rheumatic origin. See Class II. 1. 2. 17.
9. Mesenteritis. Inflammation of the mesentery is attended with pains like colic, and with curdled or chyle-like stools. It is a very frequent and dangerous disease, as the production of matter more readily takes place in it than in any other viscus. The consequence of which, after a hard labour, is probably the puerperal fever, and in scrophulous habits a fatal purulent fever, or hopeless consumption. ”

“ A lent fever, depending on some fixed cause of the bowels, must be cured by having regard to those causes some of which I shall enumerate”:—the first supposition being that the fever depends on phlegmons by congestion of “the liver, spleen, pancreas, or the mesentery”; the second, if it depends on extravasations in an equally comprehensive range of viscera; the third, “if it depends on an ulcer, then all vulneraries must be administered internally; but to speak truth, when the viscera are ulcerated, there remains but small hope of life” ”

“ From loop lp6 the large intestine, il, extends, with gradually increasing caliber, to the cloaca, cl, a distance of 10 to 15 mm.
Except in the enlarged region near the pylorus the lumen of the intestine is almost obliterated by the folding of its thick walls, so that little or nothing can be told of its lining with the naked eye.
A distinct mesentery holds the loops of the intestine in position and binds the entire enteron close to the dorsal body wall. Because of the lack of properly fixed tissue no sections of the enteron of this stage were made. ”

“ After surrounding the small intestine it becomes the posterior layer of the mesentery and so again reaches the posterior abdominal wall, down which it runs until the rectum (R) is reached. The anterior surface of this tube is covered by peritoneum to a point about 3 in. from the anus, where it is reflected on to the uterus and vagina (V) in the female and then on to the bladder (B) ; in the male, on the other hand, the reflection is directly from the rectum to the bladder. ”

“ The [Pg 38] mucous membrane of the stomach near the cardiac orifice was in some parts of a roseate hue, in others a brownish-red; while in others it was ash-coloured, and dotted with red and yellow points. Towards the pyloric orifice, less disease. The stomach contained nothing but dark green bile and mucus. The duodenum was also highly injected. Lower down, the small intestines were in places lined with a dark red and brown, and the mesentery highly injected in the portions corresponding to these spots. Intestines much inflated, and omentum dark and injected. The uterus was not examined. ”

“ The characteristics of this type of dysentery, at all events of that type of bacillary dysentery which has received of late so much attention, are acuteness of onset, often a well-marked initial fever, little tendency to relapse after the initial attack, the presence of Bacillus dysenteriœ in the stools, an initial diphtheroid necrosis of the mucosa of the large intestine, non-liability to abscess of the liver, occurrence in epidemic form and in all latitudes, and in the lunatic asylums of this and other countries. ”

“ Anything approaching a scientific description of dysentery is as yet impossible. I am obliged, therefore, in describing the clinical features of dysentery to adopt an arbitrary and unscientific classification; and to deal with effects before discussing possible causes, symptoms before etiology.
Symptoms.— In ordinary cases the leading symptoms of dysentery are those of inflammation of the great intestine namely, griping, tenesmus, and the passage of frequent, loose, scanty, muco-sanguineous stools. The illness commences in various ways insidiously or suddenly ”

“ It occurs in greatest abundance in dysenteric lesions and especially in the solitary lymphatic follicles of the large intestine, and in the mucus in the stools during the most acute stage of " epidemic " dysentery. It is pathogenic to many animals, but it does not produce in them, or only exceptionally, dysenteric lesions, although the toxins of the bacillus, pounded and killed cultures, when injected intravenously into rabbits and other animals, produce necrosis of the large intestine into which they are excreted by some selective action. ”

“ Pathology of bacillary dysentery.— The large intestine is the seat of the affection; in some cases the last few feet of the ileum also may be attacked. In early cases the gut wall is thickened and infiltrated, the mucous membrane œdematous and of a cherry-red colour showing small yellow superficial ulcers along the exposed borders and folds. In severe cases, or cases in which the disease has lasted for some time, the mucous membrane may be entirely gangrenous, of a bright-green colour, and forming what appears to be a false membrane on the surface of the bowel. ”

“ From the Accounts we have in Authors, of the Dissection of the Bodies of Persons who died of the Dysentery, it would appear; that there is no Part of the alimentary Canal which has not some time or other been found inflamed, or in a state of Suppuration or Gangrene; and the Liver, Spleen, and other Viscera, have likewise been found diseased, but the Rectum and Colon have almost in all been more or less affected. ”

“ How it attains the human intestine is not known, but as it is a common parasite of the pig and apes, in which it occasions a fatal form of dysentery, it is likely that one or other of these animals is a usual source of infection. As attempts to infect animals experimentally have failed, it is reasonable to conclude that the infusorian, on occasion, assumes some resistant form which enables it to withstand the gastric and intestinal juices on the way to its habitat, the end of the ileum and the large intestine. ”

“ DYSENTERY (from the Gr. prefix δυσ-, in the sense of “bad,” and ἔντερον, the intestine) , also called “bloody flux,” an infectious disease with a local lesion in the form of inflammation and ulceration of the lower portion of the bowels. Although at one time a common disease in Great Britain, dysentery is now very rarely met with there, and is for the most part confined to warm countries, where it is the cause of a large amount of mortality. (For the pathology see Digestive Organs.) ”

“ Although dysentery is a disease of the large intestine, its lesions are not exclusively limited to this structure. It is always a purely local disease at first, and, strictly speaking, continues so throughout its course, yet it produces in severe or chronic cases widespread and general effects. Rapid emaciation sets in, and anæmia is soon pronounced in all the internal organs. The mesenteric glands show signs of irritation or of absorption of specific products in hyperæmic pigmentation and hyperplasia. ”

“ Cælius Aurelianus gives a very comprehensive description of dysentery, the principal symptoms of which are fever, anxiety, rumbling of the belly, sometimes retention of urine; tongue rough, furred, and black; tenesmus and pungent pains of the intestines and anus. The disease, he says, consists of a defluxion from the belly with ulceration, and is preceded by diarrhœa, cholera, or inflammation. He animadverts upon the treatment of others with his usual freedom. Thus he blames Erasistratus for using nothing but astringents, whereas many cases of dysentery require laxatives. ”

“ Many attempts have been made to induce dysentery by the injection of animals, or by feeding them with material— stools, liver pus, cultures— containing amœbæ. In a proportion of instances, especially where injections were used, amœbic dysentery has resulted. But as it is impossible to secure the amœba in pure culture, unless it may be in liver pus, these experiments are open to the objection that the successes depended possibly not on the amœbæ present, but on other micro-organisms of a pathogenic nature unavoidably introduced at the same time. ”