Final answer:
The hepatic portal vein carries blood from the digestive organs to the liver, where it is processed before entering the systemic circulation. This vein is part of the hepatic portal system, which includes tributaries that collect blood from the gastrointestinal tract and spleen.
Step-by-step explanation:
The vein that carries blood from the digestive organs to the liver is the hepatic portal vein. The hepatic portal system includes the hepatic portal vein and the veins that drain into it, such as the superior mesenteric vein, which carries blood from the small intestine, stomach, and two-thirds of the large intestine, and the splenic vein, which carries blood from the spleen, pancreas, and stomach.
This portal system begins with the confluence of the superior mesenteric and splenic veins and is essential for transporting nutrients, drugs, and toxins from the digestive tract to the liver for processing before entering the systemic circulation via the hepatic veins and inferior vena cava. This ensures that the liver can modify the nutrient content and detoxify substances, maintaining stable blood composition.