Morphological study of larynx, trachea, and lungs of Didelphis marsupialis (LINNAEUS, 1758)

Vet World Vol.13 October-2020 Article-14

Research Article

Veterinary World, 13(10): 2142-2149

https://doi.org/10.14202/vetworld.2020.2142-2149

Bruna Tassia Santos Pantoja¹, Armando Reinaldo Marques Silva², Renata Mondego-Oliveira³, Thamires Santos Silva¹, Babara Carvalho Marques², Rafaela Pontes Albuquerque⁴, Joicy Cortez Sá Sousa⁵, Rose Eli Grassi Rici¹, Maria Angélica Miglino¹, Alana Lislea Sousa⁶, André Luís Resende Franciolli¹, Eduardo Martins Sousa⁵, Ana Lúcia Abreu-Silva^3,4,6, and Rafael Cardoso Carvalho^2,4

1. Graduate Program in Anatomy of Domestic and Wild Animals, Department of Surgery, Faculty of Veterinary Medicine and Animal Science, University of São Paulo, São Paulo, Brazil.
2. Center for Agricultural and Environmental Sciences, Federal University of Maranhão, Chapadinha, Brazil.
3. Northeast Biotechnology Network, Center for Biological and Health Sciences, Federal University of Maranhão, São Luís, Brazil.
4. Graduate Program in Health Sciences, Center for Biological and Health Sciences, Federal University of Maranhão, São Luís, Brazil.
5. Graduate Program in Microbial Biology, CEUMA University, São Luís, Brazil.
6. Graduate Program in Animal Science, Faculty of Veterinary Medicine, Center for Agricultural Sciences, University of Maranhão, São Luís, Brazil.

Background and Aim: From a biomedical point of view, the value of marsupials as a model of primitive mammals is indisputable. Among its species, the possum is a model that allows the study of the ontogeny of different organic systems, as well as their physiological aspects. The relevance of anatomical, functional, evolutionary, and phylogenetic study of marsupials for the development of comparative morphology is extensively documented in the literature. However, there are still many aspects to be further evaluated, as the anatomy and histology of the respiratory tract of this species. The aim of this study was to describe the morphology of the larynx, trachea, and lungs of Didelphis marsupialis.

Materials and Methods: Five adult male animals were donated to the Comparative Animal Anatomy Laboratory – LAAC/ CCAA-UFMA, for morphological studies. Specimens were washed in running water to perform biometrics. Then, they were fixed with 10% formaldehyde solution. After the fixation period, the specimens were positioned in dorsal decubitus position, for dissection of the respiratory system organs, by opening the ventral region of the neck and thoracic cavity, with subsequent removal of the pectoral muscles, ribs, and sternum. For histological analysis, fragments of 1 cm2 of the larynx (epiglottis and thyroid cartilages), trachea, and lungs were collected and fixed in 10% formaldehyde solution. Right after fixation, the fragments were dehydrated in increasing concentrations of ethyl alcohol (70, 80, 95, and 100%), diaphanized in xylene, embedded in paraffin, and sectioned into thin slices of 5 μm using a microtome. Sections were stained using the hematoxylin and eosin technique.

Results: Anatomically, the larynx starts right after the pharynx. It consisted of four cartilages: Epiglottis, cricoid, thyroid, and arytenoid. The trachea was made of dorsally incomplete cartilaginous rings. At the entrance of the thoracic cavity, it bifurcated into the left and right main bronchus. The left lung was smaller than the right lung, with two lobes (cranial and caudal). The right lung presents the cranial, middle, caudal, and accessory lobes. Histologically, the epiglottis consisted of elastic cartilage and is covered by a non-keratinized stratified squamous epithelium. Thyroid cartilage is made of hyaline cartilage covered by smooth muscle. The trachea presents hyaline cartilage, with ciliated pseudo-stratified epithelium, serous glands, isogenic groups of chondrocytes, and perichondrium. The lung consisted of bronchi, bronchioles, and alveoli, also presenting blood vessels and arteries.

Conclusion: Morphologically, the larynx, trachea, and lungs of D. marsupialis were similar to those of the other Didelphids described in the literature. Keywords: anatomy, histology, marsupials, respiratory tract.

Keywords: anatomy, histology, marsupials, respiratory tract.

How to cite this article: Pantoja BTS, Silva ARM, Mondego-Oliveira R, Silva TS, Marques BC, Albuquerque RP, Sousa JCS, Rici REG, Miglino MA, Sousa AL, Franciolli ALR, Sousa EM, Abreu-Silva AL, Carvalho RC (2020) Morphological study of larynx, trachea, and lungs of Didelphis marsupialis (LINNAEUS, 1758), Veterinary World, 13(10): 2142-2149.

Received: 02-06-2020 Accepted: 01-09-2020 Published online: 13-10-2020

Corresponding author: Rafael Cardoso Carvalho E-mail: carvalho.rafael@ufma.br

DOI: 10.14202/vetworld.2020.2142-2149

Copyright: Pantoja BTS, et al. This article is an open access article distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http:// creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.