Where does blood from the hepatic portal vein and hepatic artery flow into within the liver lobule?

Blood from the hepatic portal vein and hepatic artery flows into the liver sinusoids within the liver lobule. The hepatic portal vein carries nutrient-rich blood from the gastrointestinal tract and spleen, while the hepatic artery supplies oxygenated blood.

Once these blood sources enter the liver, they move into the sinusoids, which are specialized capillary-like vessels that facilitate the exchange of substances between the blood and the liver cells (hepatocytes). The structure of the sinusoids allows for increased permeability, enabling various substances, including nutrients, toxins, and hormones, to be processed by the liver. This unique arrangement is crucial for the liver's function in metabolism, detoxification, and synthesis of important proteins.

In contrast, the central vein collects blood from the sinusoids after it has been processed by the liver and carries it away from the lobule toward the systemic circulation. The portal triad, consisting of branches of the hepatic artery, hepatic portal vein, and bile duct, is located at the periphery of the liver lobule and is not the site where blood flows into. Bile ducts are involved in bile transport but do not play a role in the flow of blood into the liver lobule itself.