HUMAN NUTRITION

Detailed explanation-1: -The alveoli present in the lungs have thin walls composed only of a single layer of cells in order to minimize the diffusion distance. Their walls are moist which helps the gases to diffuse better. They are richly supplied with blood capillaries to ensure the efficient exchange of gases with the bloodstream.

Detailed explanation-2: -Alveoli are folded to increase their surface area to volume ratio, so more volume of air can diffuse in from the blood and and in from the bronchioles. The lining of the alveoli walls are also moist so the gases can easily dissolve.

Detailed explanation-3: -The presence of millions of alveoli in the lungs provides a large surface area for the exchange of gases. And this availability of a large surface area maximizes the exchange of gases.

Detailed explanation-4: -Here are some features of the alveoli that allow this: they give the lungs a really big surface area. they have moist, thin walls (just one cell thick) they have a lot of tiny blood vessels called capillaries.