The gastrointestinal tract performs a barrier function, which helps prevent microbial translocation (bacteria and endotoxins) from the tract into the systemic circulation. The barrier function consists of anatomical and functional components. These include: Intestinal motility from peristalsis. Bacterial stasis from ileus leads to overgrowth and translocation. The basal electrical rhythm of rhythmic oscillations of the membrane potentials of smooth muscle cells acts as a pacesetter for small intestinal motility. Epithelial cells and intercellular matrix and the mucus layer Inhibition of microbial adherence to epithelial cells by goblet cells, secretory IgA and the normal gastrointestinal microflora.
Patterns of gastrointestinal motility
A fil M
0 Propulsive: transport
1 Non-propulsive: mixing h Rhythmic segmentation
Do Pendular activity o
° Tonic contraction: sphincters ia y
Cell-mediated immunity from the gut-associated lymphoid tissue, represented by Peyer's patches in the muscularis mucosa of the small intestine.
Furthermore, microbial translocations into the portal circulation may be dealt with by the phagocytic function of Kupffer cells in the liver.
Splanchnic ischaemia results in failure of the gut barrier, leading to intracellular acidosis secondary to inadequate oxygen delivery. The gastric pH may hence be a marker of barrier function.
Was this article helpful?