How is the alveoli adapted for its job?

The ruched, cloud-like structure of the alveoli means that there is a large surface area for gas exchange between the blood and the lungs, which increases the efficiency of the process, meaning the supplies of oxygen are constantly being replenished, and carbon dioxide is constantly being depleted. In addition, each alveoli has an excellent supply of deoxygenated blood, meaning the concentration gradient between the oxygen rich alveoli and oxygen depleted blood is steep for quick diffusion. the walls of the alveoli only consist of the basement membrane, meaning that the gases do not have far to travel, which again increases efficiency of gas exchange. The basement membrane is also entierly permeable to the gases. Finally, the alveoli has a surfactant layer of liquid, dissolving the gases on the epidermal surface, which is ideal for transfer into the blood, as well as allowing for diffusion to occur much more speedily.