Descrição morfológica do diafragma do sagui-de-tufo-branco (Callithrix jacchus)

Abstract

Pesq. Vet. Bras. 32(6):553-558, junho 2012 553 RESUMO.-O músculo diafragma, encontrado apenas nos mamíferos, é o principal músculo no processo respiratório, servindo de fronteira entre as cavidades torácica e abdoDescrição morfológica do diafragma do sagui-de-tufo-branco (Callithrix jacchus) The diaphragm muscle found only in mammals is the main muscle in the respiratory process, serving as the border between the thoracic and abdominal cavities. Its signiϐicance also is highlighted in research conducted with grafts using various types of biological membranes for the repair of diaphragmatic defects which may cause diaphragmatic hernias. In spite of many studies already conducted in non-human primates, especially in regard to the new world species Callithrix jacchus (white-tufted-ear-marmoset) from northeastern Brazil, research involving use of the diaphragm in such species is nonexistent. Thus, the objective was to characterize the morphology and biometry of the diaphragm in C. jacchus of both sexes, analyzing possible structural differences between males and females. To this end, we used four adult white-tufted-ear-marmosets from a commercial breeder, two males and two females that had died of natural causes. After ϐixed in 10% formaldehyde solution, the animals were dissected for photo documentation, the diaphragm was collected for biometrics (length and width) with a caliper, and for histological processing by hematoxylin-eosin and Trichrome Masson. The measurements showed that there were no signiϐicant differences between males and females. The topography and the presence of three openings (foramen vena cava, aortic et esophageal hiatus) in the extension of the diaphragm corroborate descriptions in classical literature for other mammals. Regarding the histological ϐindings, it was concluded that the muscular ϐibers are arranged in an organized shape, with a large diameter and basal nuclei, and showed similar characteristics of skeletal muscle in males and females.

Diaphragm morphology of Guinea pig (Cavia porcellus)

“…Histologically, the examined diaphragms presented similar characteristics of other mammals, harboring three major fiber types: sternal, lumbar, and costal (Gauthier and Padykula, 1966;Lessa et al, 2012a). According to Banks (1992) and Junqueira and Carneiro (2004) muscle cells are rounded, multinucleated, presenting oval nuclei on the cell periphery; some nuclei may be centrally located due to the proximity of the sarcolema or due to the presence of artifacts, below or above the observation plane, corroborating the observations of the present study.…”

“…Concerning the tridimensional shape, the tendineous center of the "U"-shaped guinea pig diaphragm differs from the "V"-shaped tendineous center of the diaphragm of white tuffed-ear marmoset (Lessa et al, 2012a), white-fronted marmoset (Lessa et al, 2012b), white-ear opossum (Didelphis albiventris), and of albino rat (Cassel et al 2001), also differing from the "I"-shaped from the manatee (Rommel and Reynolds, 2000).…”