AP BIOLOGY

Detailed explanation-1: -The liver receives a blood supply from two sources. The first is the hepatic artery which delivers oxygenated blood from the general circulation. The second is the hepatic portal vein delivering deoxygenated blood from the small intestine containing nutrients.

Detailed explanation-2: -The hepatic artery provides the remaining one third of blood. This oxygen-rich blood comes from the heart and provides the liver with about half of its oxygen supply.

Detailed explanation-3: -Blood enters the liver through the hepatic artery and the portal vein. The blood from the hepatic artery carries oxygen and helps support liver growth. The portal vein carries blood and nutrients from the intestine and delivers them to the liver cells (hepatocytes), which perform specific liver functions.

Detailed explanation-4: -The hepatic portal system is the venous system that returns blood from the digestive tract and spleen to the liver (where raw nutrients in blood are processed before the blood returns to the heart).

Detailed explanation-5: -The veins starting from the stomach and intestine do not directly convey the blood to the posterior vena cava. Instead, they first enter the liver as a combined hepatic portal vein. The liver acts as a storehouse to regulate the number of nutrients flowing into the general blood circulation.