Anatomical aspects of the placenta of the sloth, Bradypus variegatus, Schinz, 1825

ABSTRACT

Sloth plows euterians mammals, belonging to the order Edentata, sub-order Xenarthra, infra-order Tardigrada, family Bradipodidae, which comprehend three specimen, Bradypus tridadctylus, Bradypus variegates and Bradypus torquatus. They plows few work found in the literature related to the anatomy of the placenta of this specimen. The material used in this research was consisted of 3 placentas of Bradypus variegatus of adult females (Briton, 1941) original of the Forests of the City of Recife and Zone of the Forest of the State of Pernambuco with average weight 4,2 Kg. Placentas were fixed in buffered glutaraldehyed 4 per cent, pH 7,4, 0,1M and processed goes optical microscopy. Macroscopically was observed that the placenta of the sloth is composed of discoidal lobes and had the fundal position of the uterine cavity. The fetal membranes identified were chorium, applied on the uterine surface and, amnion adherent to inner face of chorium. In the specimen examined presented vestige of allantois sack and vitelline sack in these gestational phase. Anatomically, placenta of Bradypus variegatus could be classified like chorium-amniotic. Microscopic analysis of the placenta showed endothelial cells of maternal vessel hypertrophied and fetal components without cellular limits identified. The fetal tissue presented an epithelioid aspect with fetal vessel surrounded to connective tissue and epithelioid cells or next to maternal vessel. According our description, Placenta of Bradypus variegatus could be classified microscopically in syndesmochorial and endotheliochorial