1. a) At functional residual capacity, lung and chest walls exert on each other a recoil pressure equal in module but opposite in sign.
a) At functional residual capacity, lung and chest walls exert on each other a recoil pressure equal in module but opposite in sign. Mechanical coupling is assured by pleural liquid pressure (Pliq) that is more negative than the recoil pressure of the structures. As a consequence, the visceral and parietal pleura push one against the other (as suggested by the solid deformed body). b) Actual touching between opposing pleurae does not occur because of repulsive forces between several layers of phospholipids adsorbed on mesothelial surfaces carrying charges of the same sign.
G. Miserocchi Eur Respir Rev 2009;18:
©2009 by European Respiratory Society