Faculty of Veterinary Medicine University of Zagreb
Abstract
The mammalian larynx is an organ which serves as a barrier to prevent food from entering the respiratory system, and in most mammals it is used to produce sound. Although the general morphology of the cetacean larynx has been known for a long time, its detailed anatomy has been poorly studied, which has resulted in many inconsistencies in the available literature, particularly regarding the nature of the dorsal paired cartilages of the arytenoepiglottic tube, and the mucosal folds found in laryngeal cavity. The aim of this paper is to give a comprehensive description of the structures associated with the larynx of the bottlenose dolphin (Tursiops truncatus, Montagu, 1821), using the well-known laryngeal morphology of humans and various domestic mammals as guidelines. The structure of the larynx was studied in 7 bottlenose dolphins of both sexes, using the classical dissection method on fresh specimens and some conserved with 4 % water diluted formaldehyde. Although careful dissection showed distinct morphological differences between the laryngeal cartilages of the bottlenose dolphin and terrestrial mammals, most of the muscles attached to them were consistent with that of terrestrial mammals. We present structures characteristic to the larynx of the bottlenose dolphin, such as two ligaments which are not present in domestic mammals and humans. Furthermore, based on the comparison with human and animal laryngeal anatomy, we conclude that the dorsal paired cartilages of the arytenoepiglottic tube in the bottlenose dolphin most likely correspond to the cuneiform process of terrestrial mammals, and that the median and lateral folds found in the laryngeal cavity should not be identified as vocal and ventricular folds.Grkljan sisavaca je organ koji predstavlja zaštitu od ulaska hrane u dišni sustav, a većini sisavaca služi i za proizvodnju zvuka. Iako je općenita anatomija grkljana kitova odavno poznata, detalji su slabo proučavani što je za posljedicu imalo razne nedosljednosti u dostupnoj literaturi, pogotovo na temu prirode dorzalnih parnih hrskavica aritenoepiglotične cijevi i nabora sluznice u grkljanskoj šupljini. Cilj ovog rada je iznijeti potanki opis struktura grkljana dobrog dupina (Tursiops truncatus, Montagu, 1821), pri čemu se kao smjernice rabe dobro upoznata anatomija grkljana domaćih sisavaca i čovjeka. Građa grkljana se proučavala na 7 dobrih dupina oba spola služeći se klasičnim metodama sekcije na svježim uzorcima i arhivskim uzorcima uščuvanim u 4 % -tnom formaldehidu razrijeđenim u vodi. Iako je pažljiva sekcija pokazala očigledne morfološke razlike u hrskavicama između dobrog dupina i kopnenih sisavaca, većina mišića koji se prihvaćaju za njih su odgovarajući kopnenim sisavcima. Iznosimo strukture koje su karakteristične za grkljan dobrog dupina kao što su: dva ligamenta koji nisu prisutni u čovjeka i domaćih sisavaca. Također, na temelju usporedbe s ljudskim i životinjskim grkljanima, zaključujemo da dorzalne, parne hrskavice aritenoepiglotične cijevi najvjerojatnije odgovaraju kuneiformnom izdanku domaćih sisavaca, a da se medijani i lateralni nabori sluznice grkljanske šupljine ne bi trebali poistovjećivati s glasnicama
