国生一 Stomach 国生一 Small Intestine The primary functions of stomach are storage, For its primary role of digestion and absorption,the mixing,and reducing all components to a slurry small intestine has a unique surface structure by with the aid of gastric secretions;and then which it greatly increases its effective luminal emptying these contents in a controlled manner surface area. into the upper small intestine. ·Folds 皱装 The surface tension of gastric fluid is low. The pH of gastric fluid is 1~3.5 ·Villi 绒毛 ·Microvilli微绒毛 国生 Small Intestine 国线一 ©Gallbladder胆囊 Bile produced by the liver Small intestine is the main site of Bile salts are surfactant drug absorption. Bile salts responsible for micelle formation and subsequent solubilization of monoglycerides and fatty ·Large surface area acids,allowing them to penetrate the intestinal mucosa. Highly perfused with capillaries @Pancreas胰脏 Juice:bicarbonates and enzymes .Bicarbonate secretion is capable of maintaining a neutral pH 国生 Small Intestine 国秋生 Large Intestine Three sections The large intestine has two primary functions:the absorption of water and electrolytes,and the storage ·Duodenum十二指肠30cm and elimination of fecal material.It is not the main ·Jejunum空肠240cm site of drug absorption because of its limited surface area. ·leum回肠360cm ·Cecum盲肠 ·Colon结肠 ·Rectum直肠 33 Shanghai Jiao Tong University Stomach The primary functions of stomach are storage, mixing, and reducing all components to a slurry with the aid of gastric secretions; and then emptying these contents in a controlled manner into the upper small intestine. The surface tension of gastric fluid is low. The pH of gastric fluid is 1~3.5 Shanghai Jiao Tong University Small Intestine Gallbladder胆囊 • Bile produced by the liver • Bile salts are surfactant • Bile salts responsible for micelle formation and subsequent solubilization of monoglycerides and fatty acids, allowing them to penetrate the intestinal mucosa. Pancreas胰脏 • Juice: bicarbonates and enzymes • Bicarbonate secretion is capable of maintaining a neutral pH Shanghai Jiao Tong University Small Intestine Three sections • Duodenum十二指肠 30cm • Jejunum 空肠240cm • Ileum 回肠360cm Shanghai Jiao Tong University Small Intestine For its primary role of digestion and absorption, the small intestine has a unique surface structure by which it greatly increases its effective luminal surface area. • Folds 皱襞 • Villi 绒毛 • Microvilli 微绒毛 Shanghai Jiao Tong University Small intestine is the main site of drug absorption. • Large surface area • Highly perfused with capillaries Shanghai Jiao Tong University Large Intestine The large intestine has two primary functions: the absorption of water and electrolytes, and the storage and elimination of fecal material. It is not the main site of drug absorption because of its limited surface area. • Cecum盲肠 • Colon结肠 • Rectum直肠