👉 The veins of the human body are the blood vessels that carry deoxygenated blood back to the heart. They run parallel to arteries, except that they carry blood away from the heart rather than towards it. The walls of the veins are thicker and less elastic than those of arteries, which helps them hold onto blood despite the lower pressure in the circulatory system. Veins have one-way valves to prevent blood from flowing backward.
