Histoarchitecture of tongue in adult emu birds (dromaius novaehollandiae)

Twenty apparently healthy adult emu birds of either sex were utilized for gross and histomorpological observations. Microscopically the tongue of emu consisted of epithelium, submucosa and lingual muscles and bones. The mucosa of the tongue was covered by keratinised stratified squamous epithelium on both dorsal and ventral surface. The dorsal and ventral epithelium was interrupted at regular intervals by ducts of lingual glands. Taste buds were observed in the intraepithelial in position. The lingual submucosa made up of dense, irregular connective tissue layer was observed underlying the epithelium on all parts of the tongue. The lingual glands were observed on the full width of the apex, body and root of this layer except lateral lingual papillae. The glandular acini was lined with cuboidal cells with basally located round nuclei and basophilic cytoplasum. The herbst corpuscles were large, round or oval shaped scattered randomly and closely associated with lingual glands. The corpuscles were covered by thin connective tissue capsule. The inner core was formed by loosely arranged concentric lamellae with centrally located nuclei. The core of the body of the tongue was formed by lingual skeleton. The lingual muscles were made up of skeletal muscle fibers noticed ventral to the paraglossum.