Question

1. what is the major difference between pulmonary veins and most other veins? they carry oxygenated blood to the heart. they have internal valves but no elastic tissue. they have a thin, smooth muscular layer. they have a corresponding artery.

Explanation:

Most veins carry deoxygenated blood to the heart, but pulmonary veins transport oxygenated blood from the lungs to the left atrium of the heart, which is their key distinguishing feature. Other options describe general vein characteristics (e.g., valves, thin muscle layers) or are not unique to pulmonary veins.

Answer:

They carry oxygenated blood to the heart.