Asellus Blood Flow

We use a microscope to examine the blood flow in the open circulatory system of asellus aquaticus. We are able to see the haemolymph moving through its limbs in different directions. Biology - Human Body - Learning Points. Large multicellular organisms need transport systems to carry materials around the body. In a closed circulatory system the blood is contained within a network of vessels; in an open circulatory system, a fluid called haemolymph flows around the body and supplies the cells directly with oxygen. In a double circulatory system the blood passes through the heart twice; in a single circulatory system the blood passes through the heart only once. Diffusion is the movement of liquid or gas particles from high to low concentrations. A Twig Experiment Film. Let students experience real experiments in lab conditions anywhere, from setup, method all the way through to analysis and real-world application.