Question

Very short answer type.
Normally a vein opens into a larger vein or into the heart but does not end in capillaries. Which vein/ veins in humans is/are exception to this rule?

Answer 1

The portal vein is not a true vein because it conducts blood to capillary beds in the liver and not directly to the heart. Unlike most veins, "portal vein" does not drain into the heart.