Surfactant contains?: (A) DPCC, (B) Nitros oxide, (C) Angiotensin, (D) VIP
Answer is A. The low surface tension when the alveoli are small is due to the presence in the fluid lining the alveoli of surfactant, a lipid surface-tension-lowering agent. Surfactant is a mixture of dipalmitoylphosphatidylcholine (DPPC), other lipids, and proteins.Ref: Ganong review of medical physiology 23rd edition Page no: 597