What is blood carried in?

Blood is carried in blood vessels. Blood vessels are a network of tubes that transport blood throughout the body. They include arteries, veins, and capillaries. Arteries carry oxygenated blood away from the heart to the rest of the body, while veins carry deoxygenated blood back to the heart. Capillaries are small, thin-walled blood vessels that allow oxygen and carbon dioxide to pass between the blood and the tissues.