Open Circulatory System

The Romalea guttata has an open circulatory system; within the cavity of the body, blood

flows freely and there is direct contact between the tissues and the organs. Through a single tubular vessel, the heart pumps hemolymph, which is a fluid similar to blood (in invertebrates) into the body cavity running through the head to the abdomen. These vessels are branched into chambers operating as the heart of the insect (occurs within the abdomen). Found in the heart wall are minuscule pores (holes), referred to as Ostia. The Ostia allow the hemolymph to penetrate the chambers of the heart from the body cavity; from there it is relocated as it is pushed through the chambers following the muscle contractions. Between the hemolymph and the cells within the heart chambers, waste and nutrients are exchanged prior to the hemolymph cutting into the transporting vessel to be executed from the body cavity.