ABSTRACT
The histology of the epithelium of extrapulmonary airways of amphibian is revised in this article, with special reference to the neuroendocrine system. Cell types of the epithelium differ, especially in anurans. Several regulatory peptides can be identified in the laryngotracheal epithelium. Cells positive to bombesin are found only in amphibian and urodele species, while serotonin cells are found only in the urodele. The ultrastructure of the neuroendocrine cells is similar to that described for the lung neuroepithelial bodies of the urodele or amphibian species. Intraepithelial nerves are only found in the anuran laryngeal epithelium. More studies are required to understand the neoroendocrine system in amphibians.
