Final answer:
The hepatic portal system plays a crucial role in directing blood containing nutrients and wastes from the digestive tract to the liver for processing, preventing them from entering the systemic circulation directly. This system is essential for the detoxification and regulation of blood composition. Therefore, the most appropriate correct option is B.
Step-by-step explanation:
The hepatic portal system is important because it transports blood that is rich in nutrients and waste products from the gastrointestinal tract and spleen directly to the liver. This system is critical for processing nutrients and wastes that have been absorbed from the diet, regulating blood levels of various substances, and detoxifying potential toxins. Therefore, the correct answer to the question is B: It allows nutrients and wastes to be processed in the liver instead of entering the circulation directly.
The hepatic portal vein carries this blood to the liver where substances can be stored, altered, or detoxified before they reach the systemic circulation. Through this mechanism, the liver acts as a gatekeeper for blood composition and ensures that potential toxins or imbalances do not harm other organs. Following processing in the liver, the blood exits through the hepatic veins into the inferior vena cava, eventually returning to the heart to be recirculated. Without this system, harmful substances could circulate freely and damage other tissues.