Morphological and Ultrastructural Analysis of the Heart of the Southern-Fur-Seal (Arctocephalus australis, Zimmermamm, 1783)

Author(s)

Juliana Plácido Guimarães

• Document type: Doctoral Thesis
• Press: São Paulo.
• Institution: Universidade de São Paulo (USP). Faculdade de Medicina Veterinária e Zootecnia (FMVZ/SBD)
• Defense date: 2009-12-15

Examining board members

Ii Sei Watanabe; Patricia Castelucci; Eliane Florencio Gama; Paula de Carvalho Papa; Irene Bastos Franceschini Vicentini

• Advisor: Ii Sei Watanabe

Abstract

The southern-fur-seal belongs to the order Carnivora, suborder Pinnipedia and Otariidae family lives in aquatic and terrestrial environments and thus presenting important adaptive morpho-physiological changes, between then the cardiovascular system. The heart is the central muscular organ of the circulatory system whose function is to transport oxygen and nutrients to tissues, as well as the transport of carbon dioxide. Considering the importance of this organ to the overall functioning of other body systems, this study was to aim to describe the morphology and morphometric aspects of the heart in order to establish comparisons between the heart of the southern-fur-seals with other pinnipeds and terrestrial carnivores. Therefore, hearts of southern-fur-seals (Arctocephalus australis) were used that come to death by natural pathologies. After macroscopic analysis and execution of measurements, the hearts were analyzed at the level of light microscopy, scanning electron microscopy, using cryo fracture in liquid nitrogen, and transmission electron microscopy. The heart of the fur seal-of-south is surrounded almost entirely by the lung and covered by the pericardium, having long, flat in shape. The ultrastructural aspects presented the dispositive of muscle fibers of the atrium and ventricles under the typical cardiac fibers revelry the myofibrils bundles, mitochondria with mitochondrial cristal, junction in form of plates, anastomosis between the myofibrils bundles, and electron dense granules like natriun-uretriz near to nuclear of muscle cells or along the disposal of mitochondria of the muscle fibers of atrium. (AU)