Certificate In Psychology (CPSY) Practice Exam

By the end of which month are the lungs of the fetus capable of breathing air?

1. Ninth

2. Third

3. Fifth

4. Seventh

The correct answer is: Seventh

The correct answer indicates that by the end of the seventh month of gestation, the lungs of the fetus are typically sufficiently developed to breathe air. At this stage, fetal lungs produce surfactant, a substance that reduces surface tension and prevents the alveoli (the tiny air sacs in the lungs) from collapsing. The production of surfactant is crucial for the lungs' ability to function properly after birth. Prior to the seventh month, while some lung development occurs, there is an insufficient amount of surfactant present, which makes it challenging for a premature infant to breathe air effectively. Therefore, although the fetus has been developing for several months, it isn't until the seventh month that the lungs are generally ready for respiration outside the womb. This understanding is essential for comprehending fetal development stages and the implications for preterm births.