MEDICAL PHYSIOLOGY

Detailed explanation-1: -It is established that pulmonary surfactant reduces surface tension at the air–water interface in the alveoli, thereby preventing collapse of these structures at end-expiration. In this manner, surfactant reduces the work associated with breathing.

Detailed explanation-2: -Pulmonary surfactant reduces the surface tension at the air-liquid interface throughout the lung by forming a lining layer between the aqueous airway liquid and the inspired air.

Detailed explanation-3: -When a surfactant is introduced into a liquid, their molecules migrate to the surface, which creates a layer of weakly attracted molecules, leading to a decrease in the surface tension. Once the air–liquid interface is saturated with surfactant, the molecules accumulate in the bulk of the solution and form micelles.

Detailed explanation-4: -A surfactant is a substance that reduces the surface tension of a liquid. For instance, a small puddle of water on a desk has high surface tension. But adding a surfactant such as dish soap to the puddle would reduce its surface tension and cause the water to spread out more.

Detailed explanation-5: -The alveolar cells produce a specialized liquid, surfactant, that decreases the surface tension in the airways reducing the amount of energy required to expand the lungs. When surface tension increases, more force is needed to expand the lungs, increasing the WOB.