The are both blood vessels, but have different functions. Arteries carry blood away from the heart and the veins bring blood to the heart. Arteries carry blood with more press … ure than veins, so they are thicker and more muscular.Veins have something arteries do not have and that is valves.6 people found this useful.he are both blood vessels, but have different functions. Arteries carry blood away from the heart and the veins bring blood to the heart. Arteries carry blood with more press … ure than veins, so they are thicker and more muscular.