How does the lungs structure make the lungs suitable?

Answer 1

You have the trachea, that lies in the center of your chest. You have ten major bronchi, that arise from the trachea on left and right side. Then there is branching and re-branching of the bronchi. This happens in right angles to each other, most probably. The process continue for 17 generations. Then the alveoli starts. They branch for six times. This creates the enormously large surface area of the lungs. It is about 100 square meters or 1100 square feet. This is how the lung structure is suitable. You have much efficient mechanism in case of the fish. In which the water current flows via gills. There is no dead space in in fish, like the land animals. But then, you have ample oxygen in the air as compared to water and your lungs are considered as very much efficient.