Circulatory system model rvfm 52 2599 this comprehensive schematic model of the human circulatory system includes authentic looking blood actually coloured water which flows through transparent veins arteries capillaries and the heart chamber this model s special design portrays venous blood a deep reddish purple and arterial blood a bright red to give visual reinforcement to the oxygenation and deoxygenation of haemoglobin as it travels the body s vascular network rvfm circulatory s