Lungs do not collapse during expiration because of the presence of?: (A) Hyaline membrane, (B) Dipalmitoyl phosphatidyl choline, (C) Macrophages, (D) Interstitial fluid
Answer is B. b. Dipalmitoyl phosphatidyl choline(Ref: Ghai 8/e p 169-170)Dipalmitoyl phosphatidyl choline is an important constituent of Surfactant, which prevent alveolar collapse during expiration.