1. Capillaries have muscular walls.   True   False   2. The walls of capillaries comprise a single layer of squamous epithelium.   True   False   3. The hepatic portal vein carries blood from the stomach and the intestine into the _______.   heart   lungs   kidneys   liver   Hint Half-n-half Clue   4. Which blood vessel transports blood from the aorta into the liver?   renal vein   hepatic artery   hepatic vein   renal artery   Half-n-half Clue   5. Which blood vessel carries blood from the lungs to the heart?   pulmonary vein   hepatic artery   pulmonary artery   hepatic vein   Half-n-half Clue   6. Veins have non-elastic walls.   True   False   7. Arteries have thick walls.   True   False