Final answer:
Valves in veins ensure one-way blood flow towards the heart, aided by mechanisms like the skeletal muscle pump, despite lower blood pressure in veins compared to arteries.
Step-by-step explanation:
The one-way flow of blood in veins is maintained by valves. Unlike arteries, which have thicker walls to accommodate the high-pressure blood flow from the heart, veins have thinner walls and rely on valves to prevent the backflow of blood . The skeletal muscle pump and the respiratory pump also contribute to the proper flow of blood in the veins. As blood moves from venules to veins, the pressure drops but the valves ensure unidirectional flow towards the heart, assisted by the skeletal muscle contractions, especially in the limbs.