All of the following veins are formed from vitelline vein EXCEPT:
The vitelline veins are part of the embryonic circulatory system. They drain blood from the yolk sac. During development, the vitelline veins undergo changes. Their proximal parts contribute to the formation of the portal vein and the splenic vein. The distal parts become the superior mesenteric vein and the inferior mesenteric vein. The hepatic veins, however, develop from the umbilical vein, not the vitelline. Wait, no, the hepatic veins themselves form from the fusion of the ducts from the sinusoids. Hmm, maybe I'm mixing things up here.
Wait, the hepatic veins are part of the hepatic sinusoids. The vitelline veins contribute to the portal system. The umbilical vein forms the left branch of the portal vein. The hepatic veins themselves are formed from the coalescence of the central veins within the liver. So, the hepatic veins are not derived from the vitelline veins. So the answer would be the hepatic vein. Let me check the options again. If the options include the hepatic vein, then that's the correct answer. If the options are about portal vein, splenic vein, superior mesenteric, and hepatic, then the exception is the hepatic vein.
**Core Concept**
The vitelline veins embryologically contribute to the development of the portal venous system. Key veins formed include the **portal vein**, **superior mesenteric vein**, and **splenic vein**. The **hepatic veins** arise independently from the central veins of the liver lobules.
**Why the Correct Answer is Right**
The **hepatic veins** are formed by the coalescence of central veins within the liver parenchyma, not from the vitelline veins. In contrast, the vitelline veins give rise to the **portal vein** (proximal portion) and **superior/inferior mesenteric veins** (distal portions). The **splenic vein** also derives from the vitelline system via anastomoses. This embryological distinction explains their exclusion from vitelline-derived veins.
**Why Each Wrong Option is Incorrect**
**Option A:** *Portal vein*—Derived from the proximal vitelline vein.
**Option B:** *Superior mesenteric vein*—Formed from the distal vitelline vein.
**Option C:** *Splenic vein*—Arises from vitelline vein anastomoses with the posterior cardinal veins.
**Clinical Pearl / High-Yield Fact**
Remember: **"Vitelline veins → portal system"**. The hepatic veins are a common exam trap—students often confuse them with hepatic portal system derivatives. Focus on their embryonic origin from liver lobule central veins.
**Correct Answer: D. Hepatic veins**