Question

The alveoli contain specialized cells that secrete a phospholipoprotein complex known as pulmonary surfactant. The function of pulmonary surfactant is ________________________.

• A. to provide some rigidity to the alveoli to prevent lung collapse
• B. to decrease the surface tension of the alveoli, making it easier to expand them
• C. to facilitate the diffusion of $O_2$ and $C{O}_2$ by providing protein channels through which these gases flow
• D. to provide a sticky surface upon which dust and microbes are trapped and disposed of

Answer 1

The correct option is B to decrease the surface tension of the alveoli, making it easier to expand them

Alveoli is the region in the lungs where exchange of gases takes place.According to histology of alveolar wall ,it contain 2types of cell

I.e. 1-Type-1 cell

2.Type -2 cell which secret DPPP(DIPAMITOYL PHOSPHATIDOYL CHOLINE OR LECITHINE) which acts as a surfactant and help in preventing collapsing of lungs.