Intestine large

The large intestine typically receives 500 to 1500 ml of chyme per day from the small intestine. As discussed, most digestion and absorption have 

The colon s absorption of most of the water and salt from the chyme results in this drying or concentrating process. As a result, only about 100 ml of water is lost through this route daily. The remaining contents, now referred to as feces, are stored in the large intestine until it can be eliminated by way of defecation. 

The longitudinal layer of smooth muscle in the small intestine is continuous. In the large intestine, this layer of muscle is concentrated into three flat bands referred to as taniae coli. Furthermore, the large intestine appears to be subdivided into a chain of pouches or sacs referred to as haustra. The haustra are formed because the bands of taniae coli are shorter than the underlying circular layer of smooth muscle and cause the colon to bunch up, forming the haustra. 

In contrast to segmentation contractions in the small intestine (9 to 12 per minute), haustral contractions occur much less frequently (up to 30 min between contractions). These very slow movements allow for the growth of bacteria in the large intestine. Normally, the bacterial flora in this region is harmless. In fact, some of the bacteria produce absorbable vitamins, especially vitamin K. 

A second form of motility in the large intestine is mass movement. Three or four times per day, typically after a meal, a strong propulsive contraction occurs that moves a substantial bolus of chyme forward toward the distal portion of the colon. Mass movements may result in the sudden distension of the rectum that elicits the defecation reflex. 

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Intestinal flora is a general term for the bacteria yeast and fungi that live in the large intestine... 

The largest use of endoscopic techniques is in the examination of the gastrointestinal tract. Upper intestinal endoscopy is the examination of the esophagus, stomach, and proximal duodenum. Colonoscopy is the examination of the colon, large intestine, and in some cases the distal parts of the small intestine. Cholangiopancreatography is the examination of the biUary tree and pancreas. 

Gastrointestinal x-ray imaging is the imaging of the small and large intestines and the colon. The contrast between the various tissues found in the abdomen is poor. As a consequence, a contrast agent is introduced into the digestive tract which absorbs more x-rays than do the tissues in the abdomen. 

Florfenicol concentrations in tissues and body fluids of male veal calves were studied after 11 mg/kg intramuscular doses adininistered at 12-h intervals (42). Concentrations of florfenicol in the lungs, heart, skeletal muscle, synovia, spleen, pancreas, large intestine, and small intestine were similar to the corresponding semm concentrations indicating excellent penetration of florfenicol into these tissues. Because the florfenicol concentration in these tissues decreased over time as did the corresponding semm concentrations, it was deemed that florfenicol equiUbrated rapidly between these tissues and the blood. Thus semm concentrations of florfenicol can be used as an indicator of dmg concentrations in these tissues. 

Balantidiasis (balantidiosis, balantidial dysentery), an intestinal disease seen almost worldwide, is caused by the large ciUated protozoan, balantidium coll The organism is usually found in the lumen of the large intestine of humans and animals. Cysts formed in the lumen of the colon or in freshly evacuated feces of humans or domesticated and wild animals, can colonize the colon and terminal ileum of new hosts by the latter s ingestion of contaminated food or water. The hog has been found to be the most heavily parasitized host. Its association with the rat may be a means for maintaining a reservoir infection in the two animals. 

E. histolytica colonization of the large intestine is eradicated using a luminal agent such as diloxanid furoate or paromomycin. Invasive amoebiasis (colitis,... 

Entamoeba histolytica is an anaerobic rhizopod that occurs in tropical and subtropical areas. It can cause intestinal and extraintestinal manifestations. It is transmitted orally by ingestion of cysts that develop into trophozoites in the large intestine. Amebic trophozoites release several cytolytic factors, e.g. amoe-bapore, which enable the parasite to invade tissue. In intestinal amoebiasis, E. histolyticatrophozoites invade the intestinal mucosa, causing a form of ulcerative colitis with bloody and mucous diarrhoea. Extraintestinal manifestation of amebiasis results in abscess formation, usually in the liver but sometimes in the brain. 

Tissue-Specific Expression. In adult rodents, PPAR.a is expressed in liver, kidney, intestine, heart, skeletal muscle, retina, adrenal gland, and pancreas. In adult human, PPARa is expressed in the liver, heart, kidney, large intestine, skeletal muscle (mostly slow-twitch oxidative type I fibers), and in cells of atherosclerotic lesions (endothelial cells, smooth muscle cells, and monocytes/macrophages). Therefore, regardless of... 

A2B Large intestine, bladder NECA (non-selective) Enprofylline, MRE2029-F20, MRS 17541, MRS 1706 Gs fcAMP... 

Di-D-fructose dianhydrides have been claimed to promote the growth of bifidobacteria in vitro.134 Bifidobacterium spp. are found in the large intestines of most vertebrates.135 The benefits attributed to the presence of a healthy population of bifidobacteria in the gut include inhibition of carcinogenesis,136 suppression of putrefactive substances,137 lowering of blood pressure and blood... 

Figure 5.28 LC-electrospray-MS total ion chromatogram of sulfated oligosaccharides from mucins purified from the porcine large intestine, where the annotations indicate the molecular ions observed from each component. Reprinted with permission from Thoms-son, K. A., Karlsson, H. and Hansson, G. C., Anal. Chem., 72, 4543-4549 (2000). Copyright (2000) American Chemical Society.

Diarrhea was observed in rats exposed for 5 days, 6 hours/day to both lethal and sublethal doses of P-endosulfan ( 250 mg/kg/day for males and i6 mg/kg/day for females) (Hoechst 1989b). Autopsy of animals from this study revealed that the mesenteric blood vessels of one of the surviving females exposed to 16 mg/kg/day were distended with blood, and that the small intestines of animals dying as a result of exposure were filled with a reddish fluid (500 mg/kg/day for males and 31.25 for mg/kg/day females). In contrast, no treatment-related effects were revealed by routine gross and histopathological examination of gastrointestinal tissues (stomach, small and large intestines, and pancreas) from rats exposed to doses of 27 mg/kg/day (females) and 81 mg/kg/day (males) for 30 days, 6 hours/day,... 

KRUL C, HUMBLOT C, PHILIPPE C, VERMEULEN M, VAN NUENEN M, HAVENAAR R and RABOT S (2002) Metabolism of sinigrin (2-propenyl glucosinolate) by the hiunan colonic microflora in a dynamic in vitro large-intestinal model . Carcinogenesis, 23 1009-16. 

Irrespective of the physical form of the carotenoid in the plant tissue it needs to be dissolved directly into the bulk lipid phase (emulsion) and then into the mixed micelles formed from the emulsion droplets by the action of lipases and bile. Alternatively it can dissolve directly into the mixed micelles. The micelles then diffuse through the unstirred water layer covering the brush border of the enterocytes and dissociate, and the components are then absorbed. Although lipid absorption at this point is essentially complete, bile salts and sterols (cholesterol) may not be fully absorbed and are not wholly recovered more distally, some being lost into the large intestine. It is not known whether carotenoids incorporated into mixed micelles are fully or only partially absorbed. 

To date, there is very little known about if and how phytochemicals modulate the metabolism of GIT tissues other than the liver. Of particular interest are the xenobiotic metabolizing enzymes of the GIT, which are involved with transformation of drugs and toxins. Whereas the metabolic activities of the resident microflora dominate in the large intestine, mucosal enzyme activities are more important in the small intestine where bacterial densities are lower and the villi and microvilli increase the area of exposure. 

Anti-cancer effect (Nesaretnam et. al., 1998) Human mammary and large intestinal cancer inhibition (Nesaretnam et al., 1998). 

Shamsuddin, A.M., Elsayed, A.M. and Ullah, A. (1988). Suppression of large intestinal cancer in F344 rats by inositol hex-aphosphate. Carcinogenesis 9, 577-580. 

The distribution of inflammation in CD differs from that seen in UC, as any part of the entire GI tract may be affected in CD. The small intestine is the site most commonly involved. Within the small intestine, the terminal ileum and cecum are almost always affected. Approximately 20% of patients have isolated colonic involvement, whereas inflammation proximal to the small intestine is almost never seen without the presence of small or large intestinal disease.12... 

Stimulation of 5-HT3 receptors triggers hypersensitivity and hyperactivity of the large intestine. Alosetron (Lotronex) is a selective 5-HT3 antagonist that blocks these receptors and is used to treat women with severe diarrhea-predominant IBS. Eligible patients should have frequent and severe abdominal pain, frequent bowel urgency or incontinence, and restricted daily activities. Alosetron has been shown to improve overall symptoms and quality of life. Alosetron can cause constipation in some patients. 

The large intestine consists of the cecum the ascending, transverse, descending, and sigmoid colon segments and the... 

Four major tissue layers, from the lumen outward, form the large intestine the mucosa, submucosa, muscularis externa, and serosa (Fig. 88-2). Complete replacement of surface epithelial cells occurs approximately weekly, with the total number of epithelial cells remaining constant in normal colonic tissue. As patients age, abnormal cells accumulate on the surface epithelium and protrude into the stream of fecal matter their contact with fecal mutagens can lead to further cell mutations and eventual adenoma formation.4... 

Comorbid conditions, such as chronic ulcerative colitis, particularly when it involves the entire large intestine, and to lesser extent Crohn s disease, also increase the risk of colon cancer. Overall, persons diagnosed with either disease constitute about 1% to 2% of all new cases of colorectal cancer each year. 

Familial adenomatous polyposis An inherited condition in which numerous polyps form, mainly in the epithelium of the large intestine. While these polyps start out benign, malignant transformation into colon cancer occurs 100% of the time when not treated. 

Tajima, K., Tominaga, S., Dietary habits and gastro intestinal cancers A comparative case-control study of stomach and large intestinal cancers in Nagoya, Japan, Jpn J Cancer Res, 76, 705, 1985. 

Mineral Oil Hydraulic Fluids. Subserosal hemorrhaging was observed in the small and large intestine and the omentum of a child who accidentally ingested a lethal amount of automobile transmission fluid (Perrot and Palmer 1992). 

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