Pulmonary surfactant and lung collapse

[deleted783484]

I had a question on pulmonary collapse and surfactants

I know that surfactants reduce the surface tension of the alveoli fluid because by adding the surfactant the hydrophilic molecules are able to move away underneath this surfactant if we apply a force and therefore they aren't that resistant to a force so we are able to inhale air without exerting an extremely high pressure.

What I don't understand is why would lungs collapse if we did not have a surfactant? Is it because the molecules of the fluid would form like-like interactions? And if that's the case then what prevents the molecules from the surfactant to form like-like interactions and avoiding lung collapse?

Thanks a lot!

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[Pono_0001]

hmmmm maybe others can help but my intuition tells me that it's more physics than chemistry, which makes me wonder if you understand how surfactant reduce the surface tension in the first place. But the video should help. Basically the tension can ceom from the physical elasticity from the anatomy and also the physics of surface tension( law of laplace). And in the case of a water sphere like you'll see in alveoli, pure water would have a high surface tension from dipole that would even make the radius smaller. All the lipid and protein is to disrupt that intermolecular force of water to lower the surface tension

http://hyperphysics.phy-astr.gsu.edu/hbase/ptens2.html

 

[deleted783484]

hmmmm maybe others can help but my intuition tells me that it's more physics than chemistry, which makes me wonder if you understand how surfactant reduce the surface tension in the first place. But the video should help. Basically the tension can ceom from the physical elasticity from the anatomy and also the physics of surface tension( law of laplace). And in the case of a water sphere like you'll see in alveoli, pure water would have a high surface tension from dipole that would even make the radius smaller. All the lipid and protein is to disrupt that intermolecular force of water to lower the surface tension

Thank you!!! This helped so much!

 

[Danny L]

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