Please help me... gaseous exchange?

Question

What are some of the main features of the gaseous exchange on the surface of the lungs?

Answer 1

the lungs are covered by alveolus layer which has 4 characterictics. they are

1. Large surface area.

2.are present in large numbers on the surface of the lungs.

3.richly supplied with blood capillaries.

4. one cell thick

Answer 2

The lungs as a gas exchange surfaceare:

1.Thin.

2.Moist.

3. Permeable.

4.Large surface area. (many alveoli = the surface area of a tennis court).

5. Well ventilated (breathing  brings in oxygen rich air constantly).

6.Well vascularised (good blood supply) - brings CO2 rich blood to the lungs and takes away O2 rich blood.

These conditions are perfect for diffusion of O2 from high partial pressures in the lungs into the blood and for the diffusion of CO2 from the blood into the lungs.