Blood vessel Blood vessel The blood vessels are the part of the circulatory system, and microcirculation, that transports blood throughout the human body. These vessels are designed to transport nutrients and oxygen to the tissues of the body. They also take waste and carbon dioxide and carry them away from the tissues and back to the heart. Blood vessels are needed to sustain life as all of the body’s tissues rely on their functionality.There are three major types of blood vessels: the arteries, which carry the blood away from the heart; the capillaries, which enable the actual exchange of water and chemicals
Vein Vein Veins are blood vessels that carry blood toward the heart. Most veins carry deoxygenated blood from the tissues back to the heart; exceptions are the pulmonary and umbilical veins, both of which carry oxygenated blood to the heart. In contrast to veins, arteries carry blood away from the heart. Veins are less muscular than arteries and are often closer to the skin. There are valves in most veins to prevent backflow. Veins are present throughout the body as tubes that carry blood back to the heart. Veins are classified in a number of ways, including superficial vs. deep, pulmonary