A circulatory system that allows the blood to flow out of the blood vessels and into various body cavities so that the cells are in direct contact with the blood.<ref>Wile, Dr. Jay L. ''Exploring Creation With Biology''. Apologia
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A [[circulatory system]] that allows the blood to flow out of the [[blood vessel]]s and into various body cavities so that the cells are in direct contact with the blood.<ref>Wile, Dr. Jay L. ''Exploring Creation With Biology''. Apologia