Question

Insects have open circulatory systems that directly bathe their organs with fluids. Considering that this form of circulatory system is less efficient than a closed system, how are insects able to maintain life processes at remarkably high metabolic rates?

Answer 1

The circulatory fluid is known as hemolymph. When the heart pumps hemolymph through vessels into sinuses ( various fluid-filled and air-filled spaces) where materials are exchanged between the hemolymph and cells. Hemolymph returns to the through pores, which have valves that close whenever the heart contracts.