By absorbing to the air-water interface of alveoli with the hydrophilic head groups in the water and the hydrophobic tails facing towards the air, the main lipid component of surfactant, dipalmitoylphosphatidylcholine, reduces surface tension. It also means the rate of shrinking is more regular because of the stability of surface area caused by surfactant. Pleural pressure is the pressure in the pleural space.
The surfactant component, dipalmitoylphosphatidylcholine, functions by merging with the air-water boundary of alveoli, where its hydrophilic head groups interact with water and its hydrophobic tails face towards the air. This interaction decreases surface tension and results in a more regular shrinkage rate due to the increased stability of the surface area. Furthermore, pleural pressure is characterized as the pressure within the pleural space.