Cockroaches are equipped with\xa0open type\xa0circulatory system. In this, blood is pumped by heart and flows open in body cavity. Organs floating in blood get nutrition directly. Supply of oxygen is independent through a separate\xa0closed\xa0type\xa0respiratory system.To make it more explicit, the circulatory system of cockroaches is primitive consisting of only heart and primary artery. Contrary to higher animals the oxygen supply is not dependent on circulatory system. For this there is a well developed closed respiratory system for assured exchange of gases directly by the tissues.