Jejunum

Acarbose is a nonabsorbable a-glucosidase inhibitor which blocks the digestion of starch, sucrose, and maltose. The digestion of complex carbohydrates is delayed and occurs throughout the small intestine rather than in the upper part of the jejunum. Absorption of glucose and other monosaccharides is not affected. Acarbose is adrninistered orally three times a day and chewed with the first mouthful of food. 

Darm, m. gut, intestine. — blinder —, caeeum. — dicker —, colon. — dilnner —, small intestine. — gerader —, rectum- — langer —, ileum. — leerer —, jejunum. 

Absorption of angiotensin II antagonists in Ussing chambers, Caco-2, perfused jejunum loop and in vivo importance of drug ionization in the in vitro prediction of in vivo absorption. Eur. J. Pharm. Sci. 2000, 10, 215-224. 

PSA was also shown to play an important role in explaining human in vivo jejunum permeability [18]. A model based on PSA and calculated log P for the prediction of drug absorption [19] was developed for 199 well-absorbed and 35... 

Lindahl, A., Ungell, A. L Knutson, L Lennemas, H. Characterization of fluids from the stomach and proximal jejunum in men and women. Pharm. Res. 1997, 14,497-502. 

Duodenum/jejunum 103-105 Lactobacillus Streptococcus sp. Enterococcus Enterobacteriaceae Diphtheroids Few anaerobes... 

Campylobacter spp. are gram-negative bacilli that have a curved or spiral shape. Campylobacter are sensitive to stomach acidity as a result, diseases or medications that buffer gastric acidity may increase the risk of infection. Data suggest that the infectious dose for C. jejuni is similar to that for Salmonella spp. After an incubation period, infection is established in the jejunum, ileum, colon, and rectum. 

For patients intolerant of gastric feedings or in whom the risk of aspiration is high, feedings delivered with the tip of the tube past the pylorus into the duodenum or, preferably, the jejunum are preferred. 

The food, now in a liquid form known as chyme, passes through the pyloric sphincter into the duodenum, where stomach acid is neutralized. There is wide variation in lengths of the components of the small intestine (i.e., duodenum, jejunum, and ileum) between individuals (Table 98-1). Most absorption of digested carbohydrate and protein occurs within the jejunum. Most fat absorption occurs within the jejunum and ileum. In the small bowel, breakdown of macronutrients (i.e., carbohydrate, protein, and fat) occurs both within the lumen of the gut and at the intestinal mucosal membrane surface. The absorptive units on the intestinal mucosal membrane are infoldings known as... 

The location of the tip of the feeding tube is important when considering medication administration down a feeding tube. This is particularly true if the medication acts locally in the GI tract itself. For example, sucralfate and antacids act locally in the stomach. Therefore, administration of these medications through a duodenal or jejunal tube is not logical. Likewise, for medications such as itraconazole that require acid for best absorption, administration directly into the duodenum or jejunum would be expected to result in suboptimal absorption. Absorption of drugs when administered directly into the small bowel, especially the jejunum, rather than into the stomach is another area where more research would be useful. 

Duodenum The beginning portion of the small intestine, starting at the lower end of the stomach and extending to the jejunum. 

The small intestine has the shape of a convoluted tube and represents the major length of the GIT. The small intestine, comprising the duodenum, jejunum, and ileum, has a unique surface structure, making it ideally suited for its primary role of digestion and absorption. The most important structural aspect of the small intestine is the means by which it greatly increases its... 

D Winne. The influence of blood flow on the absorption of L- and D-phenylalanine from the jejunum of the rat. Arch Pharmacol 277 113-138, 1973. 

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