Brzica, H.: Comparatve gross morphology of larynx of the dog (Canis familiaris) and bottlenose dolphin (Tursiops truncatus). Diploma Thesis. Faculty of Veterinary Medicine. Zagreb, 2005

Abstract

With this study I compared anatomy of the larynx of dog (Canis familiaris) and bottlenose dolphin (Tursiops truncatus). Two specimens conserved in 4% water diluted formalin of dog larynx and three specimens of bottlenose dolphin larynx were used which were bisected in great detail. I determined that larynx of bottlenose dolphin is positioned more rostraly than that of a dog, and it has specially developed arytenoepiglottideal tube which is positioned close to the caudoventral part of the vomer. Arches of cricoid cartilage are not ventraly fused, laminae of the thyroid cartilage are strenghned with tendinous fibres and are much wider in order to serve as attachment to much stronger laryngeal muscels than those of a dog. Arytenoid cartilages are small and attached to cuneiform or corniculate cartilages which are elongated and positioned dorsaly to epiglottic cartilage forming arytenoepiglottideal tube. Epiglottic cartilage is latero-lateraly flattened and keel-shaped. Laryngeal muscles of bottlenose dolphin are relativly stonger than those of the dog, and between muscles dorsally and laterally on the larynx lay venous plexuses. Cranial and caudal laryngeal nerves of bottlenose dolphin do not anostomize and I did not find superficial branch of cranial laryngeal nerve to m. cricothyroideus. M. thyroarytenoideus in bottlenose dolphin is platelike and does not posses mm. vocalis et ventricularis as its special part. I also have not found coresponding ligaments which form the basis for vocal and vestibular fold which also do not exist in bottlenose dolphin's larynx. Ventraly in the cavity of larynx median and lateral folds are present which expand from epiglottic cartilage, squezees between arytenoid cartilages and continue all the way to trachea. Between the folds there are small openings which form entrances in small laryngeal sacs which are situated on the place of the lateral laryngeal sac of domestic animals.