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Mayazoey
Joined 31 July 2007
→Basic Anatomy and Physiology
==== Secretions ====
==== Secretions ====
*Mucus - inhibits contact and protects the mucosal surface
*Mucus - inhibits contact and protects the mucosal surface
*Digestive enzymes -
*Digestive enzymes -
*Bile - kills some bacteria and viruses
==== Epithelium ====
==== Epithelium ====
*"Tight junctions" between epithelial cells prevent entry of macromolecules and pathogens into the intestinal tract.
*"Tight junctions" between epithelial cells prevent entry of macromolecules and pathogens into the intestinal tract.
*Commensal flora competitively inhibit attachment of pathogens to enterocytes in addition to competing for nutrition and substrates. Many also produce inhibitory growth substances that are toxic to other bacteria (McGavin and Zachary, 2007.
*Commensal flora competitively inhibit attachment of pathogens to enterocytes in addition to competing for nutrition and substrates. Many also produce inhibitory growth substances that are toxic to other bacteria (McGavin and Zachary, 2007.
==== Movement ====
==== Movement ====
*Continuous peristalsis discourages persistence of toxins and aids in their elimination from the gut.
==== Cell-mediated and humoural defences ====
==== Cell-mediated and humoural defences ====
*The lamina propria contains macrophages, B and T lymphocytes, plasma cells, and mast cells.
*Lymphoid aggregates known as Peyer's patches within the small intestine aid in immunity.
*Secretory IgA and IgM are important and help prevent attachment of pathogens to the intestinal epithelium.
=== Comparative ===
=== Comparative ===
carnivores, ruminants,horse, swine, rabbits [pictures]
carnivores, ruminants,horse, swine, rabbits [pictures]