Macroscopic Anatomy of the Lower Respiratory System in Mole rats (Spalax leucodon)

Detection of morphometrical, histological and histochemical characteristics of lung and trachea in adult local squirrel (Sciurus anomalus)

The present study aimed to identify the topography, morphology, histochemistry and histology of lung structures, bronchial divisions and trachea in adult local Squirrel (Sciurus anomalus) as a species inhabited in Iraqi environments. This work was conducted on thirty local Squirrel of both sexes (15) males and (15) females were divided into three equal groups, first for http://wsx5customurl.comanatomical perceptions, second to resin cast technique and the third for histological study. Anatomically, in both sexes, the trachea appeared as a cartilaginous structure consisting of flexible cartilaginous rings, C-like, connected by annular ligaments. It begins at the end of the cricoid cartilage from the level of the second cervical vertebra to the fourth thoracic vertebral plane; eventually, it splits into the right and left main bronchi. Count tracheal rings, the entire weight of the lung, full length, the diameter of the trachea and right and left bronchi. The trachea in females was slightly less than in males but not significantly. The bronchial tree was detected in resin cast, which was constructed of the trachea divided into left and right primary bronchi (Main bronchi), the right one was split into four secondary bronchi to enter the right lobes and two secondary bronchi to the left one. The left lung contains one lobe, whereas four lobes were observed in the right. Histologically, the wall of the trachea consists of four layers. Epithelial cells of ciliated pseudostratified columnar and goblet cells that reacted positively with PAS were covered in the mucosa. Submucosa was devoid of the tracheal glands. The Trachealis muscle is connected from the outer aspect of rings. Similarly to the trachea, the primary bronchi are structured but smaller in diameter; they break up within the lung into primary, secondary and tertiary bronchi, then it terminates in respiratory bronchioles that contain Clara cells and open at the end in the sacs of alveoli. Two types of pneumocystis were observed lining the alveoli. The current study concluded anatomically and histologically that there were no significant differences between males and females of local squirrels. The lobulation of the lung in squirrels is different from other animals. The trachea and lung histologically resembled numerous animals, however, the wall had micro morphometric changes. But, the surface lining cells of the tracheal and bronchi mucosa secrete neutral mucin, with no submucosal glands in the tracheal wall. Keywords: Trachea, Local Squirrel, Bronchial Tree, Histochemical, Lung.

Morphological and histological study of respiratory system of rabbits (Oryctolagus cuniculus)

The rabbits are considered small mammals that had, in comparison to big animals, they have a high metabolic rate and oxygen requirement. Because the larynx is located at a high angle to the oropharynx, it may immediately access the nasopharynx of rabbits categorized as nose breathers. The lungs were symmetrical in size, with the right lung being more prominent than the left and situated at the trachea's bottom. The trachea is located between the left and right bronchus. Twenty rabbits were transported to the laboratory, and by the appropriate laboratory, the instrument opened the thoracic cavity, and also the organs were filmed while the respiratory organs were removed. Due to the heart interposition and its left deviation, the left lung in rabbits is smaller than the right lung, which has just three lobes. The lungs also lack septa. The trachea is separated into two bronchi, the last of which is branched into tiny bronchioles. Achieve a histological and morphological description of rabbits' respiratory tract because the rabbits are valuable models in respiratory research due to their respiratory hyperresponsiveness, which resembles asthma in humans. The larynx is located lower than the oropharynx, where it may directly access the nasopharynx, and the rabbits are nasal breathers. The primary respiratory organs of rabbits are the left and right lung, trachea and bronchi, as in humans and rats. Still, it is supported by double cartilage in the conducting portion of the respiratory system. Keywords. Respiratory system, Oryctolagus cuniculus.

Histomorphology of the lower respiratory tract in the Indian crested porcupine (Hystrix indica)

The Indian crested porcupine (Hystrix indica) (ICP) is widely distributed in Asia; however, compared with other rodents, little is known about the structures of its respiratory system. The aim of this study was to evaluate the histomorphology of the lower respiratory portion of the ICP to provide a basis for the identification of the normal structure of this organ. The larynx, trachea and lungs of four carcasses of adult Indian crested porcupines (two males and two females) were dissected and fixed in 10% neutral-buffered formalin. The gross anatomy and histology of all specimens were evaluated. A macroscopic evaluation showed unique structures in the ICP respiratory system, including the presence of a chamber-like structure at the origin of the bronchi and a difference in epiglottis shape between males and females. Histologically, the stratified squamous epithelium covered the epiglottis and arytenoid cartilage, and the pseudostratified ciliated columnar epithelium covered the internal part of the thyroid and cricoid cartilages. Histomorphological studies showed a few goblet cells in the tracheal epithelium. In the bronchi and larger bronchioles, pseudostratified ciliated columnar epithelia were observed. Bronchi were surrounded by segments of cartilage. Distal bronchioles had a simple cuboidal/columnar epithelium with club (Clara) cells, lacked cartilaginous tissue in their walls and had a complete smooth muscle layer. These results revealed histomorphological differences between the ICP and other rodents.

Comparative morphometric analysis of lungs of the semifossorial giant pouched rat (Cricetomys gambianus) and the subterranean Nigerian mole rat (Cryptomys foxi)

Lungs of the rodent species, the African giant pouched rat (Cricetomys gambianus) and the Nigerian mole rat (Cryptomys foxi) were investigated. Significant morphometric differences exist between the two species. The volume of the lung per unit body mass was 2.7 times larger; the respiratory surface area 3.4 times greater; the volume of the pulmonary capillary blood 2 times more; the harmonic mean thickness of the blood-gas (tissue) barrier (τht) ~29% thinner and; the total pulmonary morphometric diffusing capacity (DLo2) for O2 2.3 times more in C. foxi. C. gambianus occupies open burrows that are ventilated with air while C. foxi lives in closed burrows. The less morphometrically specialized lungs of C. gambianus may be attributed to its much larger body mass (~6 times more) and possibly lower metabolic rate and its semifossorial life whereas the 'superior' lungs of C. foxi may largely be ascribed to the subterranean hypoxic and hypercapnic environment it occupies. Compared to other rodents species that have been investigated hitherto, the τht was mostly smaller in the lungs of the subterranean species and C. foxi has the highest mass-specific DLo2. The fossorial- and the subterranean rodents have acquired various pulmonary structural specializations that relate to habitats occupied.

Morphology of the Oligoryzomys nigripes respiratory system

Rodents are important in the transmission of infectious diseases that affect the respiratory tract, including simple infections and those caused by specific pathogens. These animals are natural reservoirs of zoonoses that cause many public health diseases. Basic knowledge on the morphology of these animals is important as basic research is useful for applied studies, such as the development of clinical, therapeutic, surgical and clinical models. Morphological data of respiratory tract in Oligoryzomys nigripes are absent in the literature. Therefore, the aim of this study was to perform a morphological analysis of the respiratory tract of O. nigripes. Five adult females from the environmental reserve in São Joaquim da Barra, São Paulo were used, donated to the Museum of Veterinary Anatomy (FMVZ/USP). Several morphological features follow the same pattern seen in rodents; however, this species showed some differences such as the presence of three lobar bronchi, nonlobed left lung and the right lung constituted by two lobes. Respiratory epithelium lined the whole respiratory tract and was seen using scanning electron microscopy the oval shape of the parenchyma and alveoli.

Rodentia

This chapter includes diseases of animals in the order Rodentia, in which there are over 2000 species representing 40% of all mammals. This incredibly diverse order includes members inhabiting every continent, either naturally or in human-made environments. While rodents have been the cause or implicated in disease transmission that has lead to human pandemics, such as the Black Death, and the decimation of certain animal species, like island-dwelling birds; genetically modified rodents have contributed significantly to the advancement of biomedical research and human health. There are more than 50 species of endangered rats, mice, voles, squirrels, and marmots. The recent extinction of the Bramble Cay melomys represents the first human-induced rodent extinction linked to climate change. Rodents are the reservoir host of several human and domestic pathogens of concern listed by OIE. Herein, we highlight those diseases of rodents that lead to clinically important gross and microscopic lesions.

Morfologia comparada do aparelho respiratório de capivaras (Hydrochoerus hydrochoeris)

RESUMO: A capivara (Hydrochoerus hydrochoeris), um roedor silvestre típico no continente Sul-americano, é utilizada como fonte de alimento em toda a sua região de ocorrência, sendo um importante componente na dieta de povo indígena e população rural do Brasil. O conhecimento da morfologia fornece bases para outras áreas de atuação, bem coamo, para o manejo biológico de animais silvestres. Devido à escassez na literatura de estudos anatômicos e morfológicos do aparelho respiratório da capivara, o objetivo deste trabalho é analisar os órgãos deste aparelho, macro e microscopicamente, para que possamos adquirir melhor conhecimento básico e compará-lo com o de animais da mesma subordem (Histricomorfos) e com outras espécies de mamíferos. Vimos que o aparelho respiratório da capivara é formado pelas narinas, fossas nasais, cavidade nasal, seios paranasais, faringe, laringe, traqueia e pulmões. O nariz se localiza em plano nasal com as narinas dispostas lateralmente. A maior parte da cavidade nasal está ocupada pelas conchas nasais, que se apresentam como estruturas em formato de espiral, com seus respectivos meatos. A laringe está delimitada por suas cartilagens e está em comunicação com a traqueia. A traqueia é um tubo cartilaginoso flexível e membranoso, com anéis incompletos em formato de “C”, que se bifurca em sua parte terminal, formando a carina traqueal. Os pulmões apresentam-se em pares, direito (com quatro lobos) e esquerdo (com dois lobos), localizados na cavidade torácica. As árvores brônquicas são formadas pelo brônquio primário e por uma sequência intrapulmonar que inclui brônquios intrapulmonares, bronquíolos, bronquíolos terminais e bronquíolos respiratórios.