江豚(Neophocaena phocaenoides)的静脉系统

研究了江豚的前腔静脉、后腔静脉和鳍肢血管．后腔静脉只有１根；后腔静脉在与肝静脉连接处无括约肌构造，肝门静脉的分枝上也没有括约肌；无明显肱动脉，大多数中等动脉无同名静脉伴行，而皮下体表层多条小静脉与１条小动脉伴行，形成热交换器的装置．江豚的循环系统中有适应水生生活，不善于潜水的结构特征．

The Venous System of the Finless Porpoise (Neophocaena phocaenoides)

The precava, the postcave and the vessel of the flipper of the Neophocaena phocaenoides were studied. There is jest one postcave .No sphincter can be seen between the postcave and the hepatica vein. There is also no sphincter in the branches of the portal vein. The humerus artery is not clear. Most of the middle size veins are no partner with the same named artery in the flipper. There are several small veins that accompany with one small artery that form a warming exchange arrangement in the surface layer of the subcutaneous tissue.The circulatory system of the Neophocaena phocaenoides have some characters to adapt to the water life but also have some characters to cause the finless porpoise becoming a poor diver.