Which respiratory-associated muscles would contract or relax during forced expiration,for example blowing up a balloon?
A) external intercostals would contract and diaphragm would relax
B) internal intercostals and abdominal muscles would contract
C) diaphragm contracts, internal intercostals would relax
D) diaphragm would contract, external intercostals would relax

Question

Quizplus · Accepted Answer

During forced expiration, the muscles that contract are the internal intercostals and the abdominal muscles. The internal intercostals pull the ribs downward and inward, while the abdominal muscles push the diaphragm upward, both resulting in an increase in intra-abdominal pressure that helps expel air from the lungs. The external intercostals and diaphragm would relax during forced expiration as they are involved in inhalation, not exhalation.

Which Respiratory-Associated Muscles Would Contract or Relax During Forced Expiration,for