Which situation would most likely involve active expiration?

• A. Reading a book silently
• B. Blowing up a balloon
• C. Sitting quietly and breathing normally
• D. Sleeping

Answer: (B)

Verified step by step guidance

1. Understand the concept of active expiration: Active expiration involves the use of additional muscles, such as the abdominal muscles and internal intercostal muscles, to forcefully expel air from the lungs. This is in contrast to passive expiration, which occurs naturally due to the elastic recoil of the lungs and does not require muscle contraction.
2. Analyze the scenarios provided: Determine which activities involve forceful exhalation. Passive expiration is sufficient for activities like sitting quietly, reading silently, or sleeping, as these do not require extra effort to expel air.
3. Focus on the activity of blowing up a balloon: This action requires forceful exhalation to push air into the balloon, which involves the contraction of abdominal and internal intercostal muscles. This is a clear example of active expiration.
4. Compare the physiological requirements: Blowing up a balloon demands more effort and muscle engagement compared to the other activities listed, which rely on passive expiration.
5. Conclude that blowing up a balloon is the situation most likely to involve active expiration, as it requires the active engagement of respiratory muscles to expel air forcefully.