 
 <prompt> Wetin dey act as substitute for the insect blood circulating organ? Given di previous question, write a context wey contain di answer. E fit be 1 - 20 sentences. Context: <response>: Insect wey dey breathe no dey use lung. Instead, insect respiratory system dey use internal tubes and sacs wey gases fit diffuse or dey pumped actively, to deliver oxygen directly to tissues wey need am through their trachea (element 8 for numbered diagram). Since oxygen dey deliver directly, circulatory system no dey used to carry oxygen, so e dey greatly reduced. Insect circulatory system no get veins or arteries, instead e consist of small dorsal tube wey get holes wey dey pulse peristaltically. Towards thorax, dorsal tube (element 14) dey divide into chambers and e dey act like insect heart. The other end of dorsal tube dey like aorta of insect wey dey circulate hemolymph, wey be arthropods' fluid wey be blood analog, inside body cavity.:61–65 Air dey enter through openings for sides of abdomen wey dem dey call spiracles. 