NCLEX RN Questions on Respiratory System Related

Review NCLEX RN Questions on Respiratory System related questions and content

When the diaphragm and external intercostals muscles contract, which of the following actions does NOT occur?

  • A. air moves into the lung
  • B. the intrapleural pressure increases
  • C. the diaphragm moves inferiorly
  • D. the intrapulmonary pressure decreases
Correct Answer: B

Rationale: When the diaphragm and external intercostals contract, the thoracic cavity expands, causing the lungs to expand and the intrapulmonary pressure to decrease (choice D). This decrease in pressure allows air to flow into the lungs (choice A). The diaphragm moves inferiorly during contraction, not superiorly (choice C). The intrapleural pressure actually decreases when these muscles contract, not increases, due to increased thoracic volume and decreased intrapleural pressure acting as a suction to keep the lungs inflated (choice B). Therefore, the correct answer is B, as the intrapleural pressure actually decreases when the diaphragm and external intercostals contract.