45.1 Introduction to Epithelial Cell Polarity The ability of epithelial cells in gastrointestinal (GI) track to absorb selected nutrients while secreting electrolytes, enzymes, and digestive factors depends on intracellular trafficking mechanisms that establish and maintain the polarized disruption of different…
Cholangiocytes are epithelial cells that line the biliary tree, a complex, three-dimensional network of interconnecting intrahepatic and extrahepatic bile ducts. The main physiologic function of cholangiocytes is the modification of the bile within the ductal lumen via coordinated bidirectional vectorial…
43.1 Introduction 43.1.1 Liver Anatomy and Function The cell types within the liver consist of hepatocytes, biliary epithelial cells, sinusoidal-lining cells (Kupffer cells and endothelial cells), stellate cells (formerly known as Ito cells), and cells involved in the immune response.…
42.1 Introduction One of the major functions of the hepatocyte is the removal of organic anionic compounds from the blood. These compounds include various xenobiotics as well as endogenous compounds such as bilirubin and bile acids. Many of these compounds…
41.1 Introduction Bile is a complex aqueous secretion that originates from hepatocytes and is modified distally by the biliary epithelium. As a basic “humor” in the body, the significance of bile had been recognized since antiquity. However, our understanding of…
Pancreatic secretion is regulated by highly integrated neural and hormonal influences that involve the brain, enteric nervous system, and gastrointestinal tract. Although these processes are complex they illustrate the finely regulated nature that is needed for maintaining sufficient secretion of…
Acknowledgments Support for the investigative activities of FSG come from the NIH (DK 52401 and DK098108) and a Veterans Administration Merit Award and for SP DK098108. The authors also wish to thank Professor Guy Groblewski for reviewing sections of this…
38.1 Cellular Plasticity of Gastric Acid Secretion 38.1.1 Organization of Epithelial Cells in the Stomach The stomach is organized by five concentric tissue layers: (1) the mucosal epithelium, lining the lumen of the stomach; (2) a thin layer of smooth…
37.1 Introduction Saliva is produced by salivary glands in a range of animal species and fulfills many different functions. Of particular importance are its roles in nutrition, facilitating the chewing, tasting, digestion, and swallowing of food. Striking dietary related adaptations…
There is a growing appreciation for the importance of gastrointestinal (GI) microbes in human health and disease. However, which microbes are important and how they contribute to human health and disease are only beginning to be understood. In this chapter,…