Inpatient Obstetric Nurse (NCC) Practice Exam

What is the main role of surfactant in the lungs?

1. To facilitate gas exchange

2. To prevent the collapse of the alveoli

3. To promote ciliary movement

4. To assist in lung maturation

The correct answer is: To prevent the collapse of the alveoli

Surfactant plays a crucial role in maintaining the stability and function of the alveoli, which are the tiny air sacs in the lungs where gas exchange occurs. Its primary function is to reduce surface tension at the air-liquid interface within the alveoli, which helps prevent their collapse during expiration. This is essential because if alveoli were to collapse, it would require significant effort to reopen them for subsequent breaths, leading to compromised pulmonary function. By reducing surface tension, surfactant ensures that the alveoli can expand more easily and remain open during breathing, promoting effective ventilation. This stability is vital for maintaining adequate gas exchange, as collapsed or unstable alveoli would hinder the ability to oxygenate blood and remove carbon dioxide. While surfactant contributes indirectly to gas exchange and supports lung maturation, its most immediate and significant role is to keep the alveoli from collapsing, which is pivotal for optimal respiratory function.