Hepatic portal vein anatomy

Steps:

• Identify the vein as the hepatic portal vein from its section, which connects digestive organs to the liver.
• Direction 1 traces upstream to nutrient-absorbing organs like the intestine.
• Direction 2 traces downstream to the liver for processing before entering the heart.
• Match options to portal system flow: intestine first upstream, liver first downstream.

Why A is correct:

• The hepatic portal vein carries blood from the intestine directly to the liver, per standard circulatory anatomy.

Why the others are wrong:

• B: Heart and brain are not adjacent to portal veins; brain drains via jugular veins.
• C: Kidneys drain via renal veins to inferior vena cava, bypassing portal system.
• D: Lungs receive deoxygenated blood from heart via pulmonary arteries, not veins to heart.

Final answer: A