In the human respiratory system, the 'Surfactant' is a lipoprotein complex secreted by which cells to reduce surface tension in the alveoli? MCQ with Answer and Explanation

Pulmonary surfactant is a complex mixture of lipids (primarily dipalmitoylphosphatidylcholine) and proteins secreted by Type II alveolar cells (septal cells) in the lungs. Its primary function is to reduce the surface tension of the fluid lining the alveoli. Without surfactant, the alveoli would collapse at the end of expiration (atelectasis) due to high surface tension, making it extremely difficult to re-inflate the lungs during inspiration.