The small bowel is twisted around the superior mesenteric artery.

小肠拧住了肠系膜上动脉。

Now, the portal venous system comprises of the portal vein and its tributaries, namely the Splenic and Mesenteric veins.

门静脉系统由门静脉和其支流组成，包括脾静脉和肠系膜静脉。

Protein C or protein S deficiency is also sometimes suspected when a venous thromboembolism develops in an unusual site like the portal, mesenteric, or cerebral veins.

当静脉血栓栓塞出现在不常见的部位时，也要怀疑蛋白C或蛋白S缺乏症，比如门静脉、肠系膜静脉或脑部静脉。