Certified Post Anesthesia Nurse (CPAN) Practice Exam

What describes the movement of gas between the atmosphere and the alveoli?

1. Ventilation

2. Tidal volumes

3. Pulmonary compliance

4. Respiratory rate

The correct answer is: Ventilation

The movement of gas between the atmosphere and the alveoli is best described by ventilation. This process involves the inhalation and exhalation of air, allowing oxygen to enter the lungs and carbon dioxide to be expelled. Inhalation brings fresh atmospheric air into the alveoli, where gas exchange occurs, and during exhalation, the air containing carbon dioxide is released back into the atmosphere. Tidal volumes refer specifically to the amount of air inhaled or exhaled in a single breath, indicating a measure rather than the overall process of gas movement. Pulmonary compliance relates to the lungs' ability to stretch and expand, which affects how efficiently gas exchange can occur but does not describe the movement of gas itself. The respiratory rate pertains to the frequency of breaths taken in a minute, providing a measurement of ventilation but again not defining the movement itself. Thus, ventilation is the correct term that encompasses this vital process.