Chapter 24

Electrolyte Secretion and Absorption in the Small Intestine and Colon

Kim E. Barrett

Kim E. Barrett

University of California, San Diego, CA, USA

Search for more papers by this author
Stephen J. Keely

Stephen J. Keely

Royal College of Surgeons, Dublin, Ireland

Search for more papers by this author
First published: 27 November 2015
Citations: 5

Summary

The balance between absorption and secretion must therefore be closely regulated. Both the small intestine and colon have a reserve capacity for absorption, but if this is exceeded, or if absorption is inhibited and/or secretion is stimulated excessively, diarrhea results. Fluid movement into and out of the intestinal lumen depends on the active secretion and absorption of electrolytes. The primary functions of the intestinal epithelium are to act as a barrier that prevents the uptake of harmful substances from the intestinal contents, and to transport fluids, nutrients, and electrolytes into and out of the gut. Substances may traverse the intestinal epithelium by multiple routes. The functional polarity of epithelial cells is the basis for this net movement of electrolytes. Molecular information about transporters and their regulation has provided insights into the diarrheal symptoms that accompany complex, not strictly genetic, disorders, such as inflammatory bowel diseases and enteric infections.

The full text of this article hosted at iucr.org is unavailable due to technical difficulties.