Question

Mr. Jones is a 44-year-old man admitted to the hospital after inhalation of smoke in a house fire. His physician tells him that he has reduced compliance and high alveolar surface tension and Mr. Jones wants to know what this means based on his situation. What would you tell him?

Answer 1

Gas exchange occurs int he alveoli of lungs, these alveoli are highly elastic structure, as we breathe the alveoli expand and as we exhale the alveoli returns to its non inflated size, one of the reason why the alveoli is so elastic it is due to the surface tension of water molecules on the alveoli themseleves, surface tension is the force exerted by the water molecule on the surface of th elung tissue as water molecules pull together,as the air inside the lungs is moist, there is considerable surface tension within the tissue of the lungs which helps the alveoli function properly. Because the alveoli of the lungs are highly elastic, they do not resist surface tension on their own, which allows the force of that surface tension to deflate the alveoli as air is forced out during exhalation by the contraction of the pleural cavity.

The force of surface tension in the lungs is so great that without something to reduce the surface tension, the airways would collapse after exhalation, making re-inflation during inhalation much more difficult and less effective. Surfactant is the molecule that reduces the surface tension from water molecules on the lung tissue,The net result is that the surface tension of the lungs from water is reduced so that the lungs can still inflate and deflate properly without the possibility of collapse from surface tension alone.

In this case the individual after inhaling smoke, could have deactivated the surfactant present in the lungs, which resulted in high alveolar surface tension, moreover the smoke would have reduced the compliance of lungs, which means alveoli will become stiff like a tube instead of being elastic which could cause him breathing difficulty