Here's a concise script timed for under a minute (about 130 words, roughly 45-55 seconds at a natural speaking pace):
Portal Vein: Anatomy and Course
"The portal vein is the main channel that carries nutrient-rich, but deoxygenated, blood from the abdominal digestive organs to the liver. It's formed behind the neck of the pancreas, at the level of vertebra L2, by the union of the splenic vein and the superior mesenteric vein.
From there, it ascends toward the liver, passing posterior to the first part of the duodenum before entering the right free margin of the lesser omentum. Within the omentum, it lies posterior to both the bile duct on its right and the hepatic artery proper on its left, together forming the portal triad.
On reaching the liver, the portal vein divides into right and left branches, which enter the liver and ultimately drain into the hepatic sinusoids. Along its course, it also receives the gastric, cystic, and para-umbilical veins."
Source: Gray's Anatomy for Students, p. 417.
Note: I opened your attached poster PDF, but no extractable text came through (it looks like an image-based/graphic poster), so I wasn't able to tailor the script to match its specific wording or layout. If you'd like the script aligned to particular terms or headings used on your poster, let me know and I can adjust it.