Identification of the tributary branches of the hepatic portal vein in the common sloth, Bradypus variegatus Schinz, 1825 (Pilosa: Bradypodidae)

ABSTRACT Bradypus variegatus, the common sloth, belongs to the Bradypodidae family, being considered a biological model to be applied in multidisciplinary research. This study was developed with the aim of being applied to clinical medicine and to the adequate management of the common sloth. Ten sloths were utilized, obtained post-natural death. The animals were fixed and to obtain the results, they were submitted to the dissection technique. For 80% of the animals, the portal vein originated from five tributaries, which were: the resulting vein from the anastomosis of the cardia vein, fundic vein, and the pyloric branches; the mesenteric trunk; the vein formed by the confluence of the stomach body branches and the cranial portion of the cavity of the cardia; the pyloric vein and splenic vein. While in 20% of the animals, the portal vein was comprised of six tributaries, because the fundic vein and cardia vein form two direct anastomoses, arriving at the portal vein two tributary vessels. This pattern differs in number and arrangement of branches when compared to the main domestic species. Therefore, the hepatic portal system is responsible for the drainage of the stomach, spleen, pancreas and intestines.

摘要
褐喉树懒（Bradypus variegatus），俗称普通树懒，隶属于树懒科（Bradypodidae），被视为可应用于多学科研究的生物模型。本研究旨在服务于临床医学领域，并实现普通树懒的规范化管理。研究共使用10只自然死亡后获取的树懒，对其实施固定后采用解剖技术开展实验以获取相关结果。结果显示，80%的个体其门静脉（portal vein）由5条属支构成，分别为：由贲门静脉、胃底静脉与幽门支吻合形成的静脉；肠系膜干；由胃体分支与贲门腔颅侧段汇合形成的静脉；幽门静脉与脾静脉。而剩余20%的个体，门静脉由6条属支组成，这是由于胃底静脉与贲门静脉形成两处直接吻合，最终有2条属支汇入门静脉。该分支的数量与排布模式与主要家养物种存在差异。综上所述，肝门静脉系统（hepatic portal system）负责收集胃、脾、胰及肠道的静脉血液。