The difference between veins and arteries is the following: first, the role of arteries and veins is different, veins are the vessels that transport metabolic waste out of tissues and organs, arteries are the vessels that transport oxygen to tissues or organs. Arteries are more important for tissues and organs, and if a vein is missing, it can compensate for the circulation through other side branches; secondly, although arteries and veins are both blood vessels, they have different tissue structures. The arterial blood vessel wall is thicker than the venous blood vessel wall, and the arterial blood vessel wall can contract on its own, but the venous blood vessel cannot contract on its own, and the venous blood vessel of lower limb has venous valve, but the arterial blood vessel has no valve; Third, the blood circulation is different, the blood circulation in the artery mainly depends on the contraction of the heart and the extrusion of the artery, and the blood circulation in the vein mainly depends on the diastolic and suction effect of the heart, and the venous reflux is affected by the body position and gravity. Larger.