Do Flies Have Lungs?
WouterA question you might have is: “Do flies have lungs?” Fly’s lungs are not unlike ours. They are long, branching tubes that carry air. However, unlike ours, their lungs do not contain a central area for breathing. Rather, they have air tubes that lead to different parts of their body. These tracheae, which are similar to the circulatory system of humans, carry oxygen-containing air to the cells.
A fly’s tracheae are made up of a network of tiny tubes that lead to the abdomen. Air enters through rows of holes in the abdomen and diffuses down these tubes. The larger bugs have the longest tracheae, which should give them the most oxygen to breathe. However, environmental oxygen pushes air into the deepest part of these tubes.
In contrast, cockroaches have a highly efficient respiratory system, but no lungs. Cockroaches take in air via external valves called spiracles, and transport it directly to their cells through tubes called trachea. Fish, on the other hand, take in water through gills on both sides of their mouths.
The air travel distance of oxygen depends on the concentration of oxygen in the air. The higher the concentration, the further oxygen can travel. Increased atmospheric oxygen levels during the Paleozoic may have helped speed up oxygen transport and allowed bigger insects to have longer tracheae. This may have also facilitated the evolution of giant species.
