Stomach pyloric sphincter

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... 

Postpyloric feeding Delivery of nutrients via a tube placed with its tip past the pyloric sphincter separating the stomach from the duodenum. 

Gastrointestinal sphincters are formed where the circular layer of smooth muscle is thickened. Sphincters occur at several points along the tract. Their function is to limit the movement of food materials from one region to another. For example, the pyloric sphincter found between the stomach and duodenum of the small intestine plays an important role in limiting the rate of gastric emptying. Sphincters undergo tonic contractions that may be sustained for minutes or hours. 

Pyloric sphincter hypertrophy, enlarged stomach Huang et al. (1993)... 

To understand the special constraints of herbivorous fishes, it helps to first understand the carnivore digestive process.40412 Carnivorous fishes consume food in which nutrients are generally readily available and of high quality (protein rich). In these fishes, food is usually broken down in the stomach through a combination of muscular contractions of the stomach wall and enzymatic action in an acid medium. Breakdown products are expelled from the stomach through the pyloric sphincter into the intestine in a process called gastric evacuation. Digestion and food absorption are completed in the intestine.40412... 

The fasting stomach pH is about 2 to 6. In the fed state, the stomach pH is about 1.5 to 2, due to hydrochloric acid secreted by parietal cells. Stomach acid secretion is stimulated by gastrin and histamine. Mixing is intense and pressurized in the antral part of the stomach, a process of breaking down large food particles described as antral milling. Food and liquid are emptied by opening the pyloric sphincter into the duodenum... 

Secretin is a 27-amino-aeid polypeptide that is slruciurally. similar to glucagon. The presence of acid in the. small intestine is the most important physiological stimulus for the secretion of secretin. The primary action of secretin Ls on pancreatic acinar cells that regulate the secretion of water and bicarbonate. Secretin also promotes the secretion of pancreatic enzymes, to a lesser extent. Secretin inhibits the release of gastrin and. therefore. ga.slric acid. It also increases stomach-emptying time by reducing the conlraction of the pyloric sphincter. ... 

Duodenal ulcer A peptic ulcer located in the duodenal is called a duodenal ulcer, and is caused by hypersecretion of acid from the stomach because of insufficient buffers to neutralize the acid, incompetent pyloric sphincter, or hypermotility of the stomach. Duodenal ulcer results in burning pain 2 to 3 hours after eating. 

The pyloric sphincter is a circular muscle at the end of the stomach leading to the duodenum that controls emptying of the stomach contents. 

In the stomach, food is converted into a semi-fluid, homogeneous, gruel-like material (chyme) that passes through the pyloric sphincter into the small intestine. The small intestine consists of three parts the duodenum, jejunum, and ileum. In the adult human, the small intestine is approximately 2 to 3 m long and decreases in cross-section as it proceeds dis-... 

The exact site of absorption of strontium in the gastrointestinal tract is not known however, studies in hamsters suggest the possibility of absorption in both the stomach and small intestine. In hamsters that received a gavage tracer dose of 85SrCl2, 37% was absorbed, whereas 20% was absorbed when the dose was administered to hamsters that had their pyloric sphincter ligated (Cuddihy and Ozog 1973). Studies in preparations of in vitro and in situ isolated intestine of the rat provide direct evidence for strontium absorption in the small intestine (see Section 3.5.1). 

Morphine can enter the mammalian body through the lining of the mouth, rectum, and unidentified portions of the intervening section of the alimentary canal (1). The seeming rule that massive doses of morphine are fatal less often than somewhat smaller amounts may mean that none is absorbed from the stomach, and that the first installment of the massive dose to be absorbed from the intestine leads to a closure of the pyloric sphincter so intense that the little morphine leaking past later can be excreted or destroyed about as fast as absorbed, whereas sufficient of a smaller dose may be absorbed from the intestine to initiate a fatal outcome before the pylorus closes. 

The stomach is a hollow organ that holds between 1000 to 2000 mL of contents that takes about 2-3 hours to empty. It, too, has two sphincters. These are the cardiac sphincter (located at the opening of the esophagus), and the pyloric sphincter (that connects the stomach to the head of the duodenum). 

Mann thought a neostomal ulcer appears when the intestinal mucosa is deprived of the protection of duodenal, pancreatic, and biliary secretions and where it is exposed to acid from the stomach. In order to imitate this situation, Mann and his young assistant, Carl S. Williamson, first made the duodenum drain its own secretions and those of the pancreas and liver at a distance from the pylorus. This was accomplished by section of the intestine at the pyloric sphincter and inversion and closure of the duodenal end. Then the intestine was sectioned at the first portion of the jejunum, and an end-to-end anastomosis of the jejunum to the pyloric sphincter was made. Finally, an end-to-side anastomosis of the duodenum to the ileum was constructed to allow duodenal, pancreatic, and biliary secretions to drain into the intestine. 

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