Respiratory distress syndrome in premature infants is due to inadequate secretion of which one of the following lipids
**Core Concept**
Respiratory distress syndrome (RDS) in premature infants is a condition characterized by impaired lung function, leading to difficulty breathing. This condition is primarily caused by the lack of a specific lipid that is essential for surfactant production in the lungs.
**Why the Correct Answer is Right**
Surfactant is a complex mixture of lipids and proteins that reduces surface tension in the alveoli, allowing for easier lung expansion during inhalation. Premature infants often have underdeveloped lungs and may not produce sufficient amounts of surfactant, leading to RDS. The main lipid component responsible for surfactant production is phosphatidylcholine, specifically its component dipalmitoylphosphatidylcholine (DPPC). However, among the options provided, the key lipid responsible is actually phosphatidylglycerol (PG), which is crucial for maintaining the integrity and function of the surfactant complex.
**Why Each Wrong Option is Incorrect**
**Option A:** Phosphatidylethanolamine (PE) is another lipid component of surfactant but is not the primary cause of RDS in premature infants.
**Option B:** Cholesterol is a component of surfactant but is not directly responsible for its function or the primary cause of RDS.
**Option C:** Sphingomyelin is a type of sphingolipid found in cell membranes but is not a primary component of surfactant.
**Clinical Pearl / High-Yield Fact**
Premature infants with RDS often require exogenous surfactant administration to improve lung function and oxygenation. This is a critical intervention that can significantly impact the outcome of these patients.
**Correct Answer:** C.