Skip to content

Category Archives: Gastroenterology

Ammonia and Urea Cycle


Ammonia (NH3) is a small metabolite that results predominantly from protein and amino acid degradation. It is highly membrane-permeant and readily crosses epithelial barriers in its nonionized form. Ammonia does not have a physiologic function. However, it is important clinically because it is highly toxic to the nervous system. Because ammonia is being formed constantly […]

Pancreatic Secretion and Its Regulation


Overall View of Pancreatic Secretion Regulation Pancreatic secretory activity related to meal ingestion occurs in cephalic (20-25%), gastric (10%), and intestinal phases (~60-70%). Pancreatic secretion is activated by a combination of neural and hormonal effectors. During the cephalic and gastric phases, secretions are low in volume with high concentrations of digestive enzymes, reflecting stimulation primarily […]

Gastric Secretion and Its Regulation


Regulation Mechanism of Gastrirc Secretion Short and Long Reflexes Neural input provides an important mechanism for regulation of gastric secretion. Reflexes contribute to both the stimulation and inhibition (e.g., CGRP) of secretion. For example, distension of the stomach wall, sensed by stretch receptors, activates reflexes that stimulate acid secretion at the level of the parietal […]