Circulation
The complete circulation:
One-way flow
Blood must flow one way only through the circulatory system. Valves in the Muscular organ that pumps blood around the body., Main artery which carries oxygenated blood from the heart in mammals. and A blood vessel with valves that transports blood to the heart. ensure this one-way flow.
Closure of a The structure in veins that prevents the backflow of blood. prevents back flow.
Cross-section through valve
