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The circulatory system of invertebrates

7-grade · Chapter: Transport of substances in living organisms

In this topic

Why circulation is needed
Animals with no circulation
Annelids — the first closed system
Open systems: molluscs and arthropods

Key terms

Circulatory system
Diffusion
Closed system
Open system
Haemolymph
Heart
Dorsal vessel
Ventral vessel
Ring vessels
Haemoglobin
Haemocyanin
Trachea

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