Inpatient Obstetric Nurse (NCC) Practice Exam

Surfactant is composed primarily of which two phospholipids?

1. Cholesterol and sphingomyelin

2. Phosphatidylcholine and phosphatidylserine

3. Lecithin and phosphatidylglycerol

4. Phosphatidylcholine and phosphatidylethanolamine

The correct answer is: Lecithin and phosphatidylglycerol

Surfactant is a crucial substance produced by the lungs, particularly in the alveoli, and plays a vital role in reducing surface tension, thereby preventing the alveoli from collapsing during exhalation. The primary components of surfactant are phospholipids, which are essential for its function. Lecithin, also known as phosphatidylcholine, is the most abundant phospholipid in surfactant and is essential for its surface-active properties. It contributes significantly to the reduction of surface tension in the alveoli, allowing for easier expansion of the lungs during breathing. Phosphatidylglycerol complements lecithin in surfactant composition. It enhances the surface activity of surfactant, particularly when the lungs are exposed to air for the first time after birth. The presence of both lecithin and phosphatidylglycerol is critical in ensuring adequate lung function, particularly in premature infants who may be at risk for respiratory distress syndrome due to insufficient surfactant production. This combination of phospholipids is instrumental in maintaining airway patency and facilitating normal gas exchange, marking surfactant as an essential substance within pulmonary physiology. Understanding the composition of surfactant helps healthcare providers assess respiratory health and the management