Small intestine

“ The sphincter between the stomach and small intestine is operated by hydrochloric acid, making up a remarkably ingenious arrangement for securing the emptying of the stomach as fast as the food is ready to be passed on into the small intestine. In order that gastric digestion may have full opportunity, it is necessary that the food should be thoroughly mixed with the gastric juice. ”

“ As the food passes along the colon, pushed slowly ahead by the peristaltic wave, or rhythmic muscular contractions of the intestinal wall, it is seized upon by the four hundred varieties of friendly bacteria which inhabit the intestines of every healthy person, and is changed into a form which the body can assimilate. Digestion in the stomach and small intestine is carried on by means of certain digestive juices, but in the large intestine it is the bacteria which do the work. ”

“ And it is not at all strange that they should, since there is so much pressure from within, so much pressure downward, and so much pressure from without—all through the requirements of fashion, indulgence, and ignorance. But the stomach, upper portion of the duodenum, and small intestine, cæcum, the ascending colon, and especially the transverse colon and sigmoid flexure, are susceptible to various forms of displacement, inhibiting the ready flow or passage of food stuffs, gases, and feces from one segment of the digestive apparatus to another, until the vent is reached. ”

“ Constipation may be absolute, without the discharge of either feces or gas. Very often the contents of the bowel below the obstruction are discharged. The abdomen is usually distended and when the large bowel is involved this is extreme. If it is high up in the small intestine, it may be very slight. At first, the abdomen is not tender, but later it becomes very sensitive and tender. The face is pale and anxious and finally collapse symptoms intervene. The eyes are sunken, the features look pinched and a cold, clammy sweat covers the skin. The pulse becomes rapid and weak. ”

“ Within this loop is a long pinkish gland, the pancreas, which empties by a duct into the duodenum. Into the duodenum also the overlying liver empties its secretion of bile from the median-placed gall-bladder. From the duodenum the small intestine or ileum extends with many convolutions to its exit through the cloacal aperture. On the intestine near the cloacal opening note a pair of glandular structures, the cæca. The short part of intestine between the cæca and cloaca is called the rectum. On the left side of the body beneath the gizzard note a dark glandular structure, the spleen. ”

“ Intense inflammation of the small intestine may exist without diarrhoea or other symptoms betokening the real nature of the attack. Flint30 mentions having met with three such instances, and Goodhart31 records thirteen cases of enteritis with marked lesions in which no diagnosis had been made before death. Rilliet and Barthez report twenty-four autopsies in children with intestinal lesions in which no symptoms had been observed.32
30 Clinical Medicine, Philada., 1879, p. ”

“ R, reticulum; C, abomasum; V.c.d., right pouch of the rumen; Ig, small intestine.
116It is by methodically observing, grouping, and classifying the symptoms presented that one is enabled to detect the links connecting them.
Intestine. The intestinal mass is contained in the right half of the abdomen above the compartment of the stomach. The large intestine occupies the upper zone, corresponding externally with the hollow of the flank from the thirteenth rib to the haunch. The small intestine occupies the middle zone from the thirteenth rib to the entrance to the pelvis and the stifle region ”

“ Millions on millions of these glands, lacteals and follicles in the stomach and small intestines, are destroyed like the rootlets of a plant or tree in unwholesome soil. The active circulation of the digestive fluids ceases, and the sufferer is said to be costive or to have chronic diarrhea. Both symptoms are the outgrowth of many years of intestinal foulness, and indicate the degree and character of intestinal irritability and semi-starvation of the body, as a consequence of either the absorption of poisons or the excessive elimination of the vital substance of the body through diarrhea. ”

“ As has been pointed out, inflammation, septic poisoning, intestinal foulness, or retained feces, act as irritants on the mucous membranes, thereby drawing the blood to the colon where it is excreted and exhaustion follows. The great danger in diarrhea, therefore, is the rapid depletion of the vital force. But when the small intestines are affected the consequences may be still more deplorable. Then the unassimilated food is hurried along too quickly for absorption and the body receives but little nourishment to restore its powers. ”

“ In the large intestines there are no villi, but the whole surface is covered with follicles which must be capable of absorbing as well as of secreting, as it is ascertained that persons can be nourished and kept alive for many weeks by nutritious enemata which do not pass into the small intestines. ”

“ A physician, who understands what he is about, knows very well, when a case of this nature comes before him, that it may proceed from a variety of causes; that it may arise in the stomach from a want of digestive power, from the small intestines by a partial failure in the process of chymification; that it may depend upon the morbid action of the large intestines, or exist merely [Pg 245] as a symptom of an affection in other organs. Sedentary habits, or irregularities of diet, are causes which may be supposed to act locally on the digestive organs themselves ”

“ Brinton, in his excellent book on Intestinal Obstruction, makes the average age in these cases fifty-three and a half [p. 839] years, and from the statistics he has gathered it will be seen that their occurrence is four times as often in females as in males. In 41 cases collected by Leichtenstern, 32 were women and 9 men. The site of the impaction is always in the small intestines. In 32 cases observed by Leichtenstern, 17 were found in the lower part of the ileum, 10 occupied the duodenum and jejunum, and 5 the middle part of the ileum. ”

“ The retention of fluids, transuded serum, bile, intestinal juices, and partly-altered food is hurtful. Decomposition sets in and gas is developed, which by distending the bowel causes great suffering and increases the inflammation. The movements of the intestine are not entirely under control; the patient must be fed; digestion and assimilation involve the activity of inflamed parts. The stomach can be made to do most of the work, but the sympathy of action is so close between the stomach and intestines that one cannot function without the other being excited into activity. ”

“ This is owing to the frequent concurrence of the two conditions, the gastric symptoms taking precedence of the others. The more complex nature of the intestinal function is another reason, intestinal indigestion having more modifications in its phenomena. In the stomach there is only one active secretion; in the intestine there are three, all participants in the act of solution. An alteration in the quality or quantity of one of these—the bile, for example—would lead to different symptomatic results than would follow another defective secretion, as that of the pancreas, for instance. ”

“ The integrity of the functions of the intestines is of supreme importance, for it is here that absorption and assimilation of most 183of our food occurs. If our intestines are not in perfect order we shall soon waste and dwindle away, even within a short period, and sometimes very rapidly. Thus if we wish to retain our strength we must treat the intestine with the greatest care. This is especially the case in old age, for then an atrophy of the glandular mechanism of the digestive tract, stomach, and intestines, takes place. ”

“ Sometimes, extremely constipated people have almost constant runny bowels because the colon has become so thickly and impenetrably lined with old fecal matter that it no longer removes much moisture. This condition is often misinterpreted as diarrhea. The large intestine's most important task is to transfer water-soluble minerals from digested food to the blood. ”

“ But when food contains no irritating substances and is easily assimilated without forming residues, or when the innervation by the vagus is sluggish and the peristaltic movements are slow, the contents of the intestines can remain longer, especially in the haustra of the intestines. It may be that the bowels move every day, but that does not prove that everything in the intestines has been expelled therefrom, for some amount of fæces can yet remain in the haustra of the intestine even for many days ”

“ 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. ”

“ If the constipation ends in fecal accumulation, the worst symptoms of mechanical obstruction may present themselves at any time, and death of the individual follow. The practitioner should always keep this fact in mind in treating every case of intestinal obstruction, and search for fecal impaction by examining the rectum and the whole length of the large intestine through the anterior abdominal wall. ”

“ The patient must have suitable nourishment and stimulation, and requires to have the greatest care, whatever special form of treatment is being carried out, while constant watch must be kept for the appearance of any complication. Great differences in the treatment are observed in different countries and by different schools of medicine.
Enteri ́tis (Gr. enteron, intestine) is inflammation of the intestines. It varies from a mild intestinal catarrh, causing slight symptoms, and yielding to treatment in a few days, to cases of severe vomiting and diarrhœa with extreme prostration. ”

“ The muscles in the colon only contract when they are stretched, so it is the volume of the fecal matter stretching the large intestine that triggers the muscles to push the waste material along toward the rectum and anus.
Eating food lacking fiber greatly reduces the volume of the chyme and slows peristalsis. But moving through fast or slow, the colon still keeps on doing another of its jobs, which is to transfer the water in the chime back into the bloodstream, reducing dehydration. So the longer chime remains in the colon, the dryer and harder and stickier it gets. ”

“ Normally the intestine contains an extremely large number of different microbes, which may prove of service so long as circulation, secretion, and peristalsis continue normal; but as soon as any perturbation occurs, either in the blood supply or in the movement of the bowel, normal secretion is impeded; abnormal organic fermentation commences, producing irritant principles or toxins which at once set up local irritation, or, being absorbed, produce that complex of symptoms which we recognise as enteritis, intoxication of intestinal origin, or even infection. ”

“ ENTERITIS. Enteritis consists in inflammation of the intestine, or, more precisely, in inflammation of the intestinal mucous membrane. All the constituent portions of the intestinal tube may be affected (duodenum, jejeunum, ileum, colon, cæcum) ; but clinical distinctions and localisation of inflammation in the various parts are very difficult in the domesticated animals, and at present it is impossible to describe with any accuracy the differences between duodenitis, enteritis of the jejeunum and ileum, colitis or typhlitis. ”

“ The intestine is straight from one end to the other but in this straight, and consequently short intestine, is a winding, cork-screw, spiral passage, through which the food, not without several circumvolutions, and, in fact, by a long route, is conducted to its exit. Here the shortness of the gut is compensated by the obliquity of the perforation.” This structure of intestine, which all the true Placoids possess, and at least the Sturiones among existing Ganoids, seems to have been an exceedingly common one during both the Palæozoic and Secondary periods. ”