Question

How are alveoli designed to maximise exchange of gases?

Answer 1

Alveoli provide a surface for the exchange of gases. An extensive network of blood vessels is present in the wall of the alveoli. By lifting our ribs and flatten the diaphragm, the chest cavity becomes spacious. Air is sucked into the lungs and alveoli. The oxygen from the breath, diffuses into the blood and CO2 from the blood brought from the body, diffuses out into the air.
@harsh

Answer 2

Alveoli have large outer surface area which can spread up to an area of 80 square metres. This helps in maximizing the exchange of gases between the blood vessels present in alveoli and the gases contained in lungs which are Oxygen and Carbon dioxide