Blood vessels are the tubes that carry blood throughout the body. Veins, which have five letters, are responsible for carrying deoxygenated blood from the body back to the heart. ARTERIES, with eight letters, are responsible for carrying oxygenated blood away from the heart to the body. Venae, also with five letters, are veins that return blood to the heart from the lungs. Capillaries, with eleven letters, are the smallest of the blood vessels and are responsible for exchanging oxygen and nutrients between the ARTERIES and veins. Lastly, vasa, with four letters, are the smallest of the blood vessels and are responsible for transporting blood to and from organs.