Here are the key differences between arteries and veins:
- Structure: Arteries have thicker, more muscular walls than veins to withstand the higher blood pressure from the heart. Arteries also have a smaller lumen (inner opening) that is round, while veins have a larger, irregularly shaped lumen.
- Blood flow: Arteries carry oxygenated blood away from the heart to tissues and organs. The blood is under high pressure. Veins carry deoxygenated blood back to the heart at a lower pressure, having to work against gravity.
- Valves: Veins contain one-way valves to prevent backflow of blood, while arteries do not have valves.
- Tunica