[Campbell Biology P.994] Which of the following statements correctly describes a characteris... | Practice Question

Which of the following statements correctly describes a characteristic of typical mammalian breathing, as explained in the text?

  • A: Both inhalation and exhalation are active processes requiring muscle contraction.
  • B: During inhalation, the diaphragm relaxes and moves upward.
  • C: During exhalation, the thoracic cavity volume is reduced due to muscle relaxation.
  • D: The rib cage only expands during exercise, not at rest.

Explanation

The text states that 'exhalation is usually passive. During exhalation, the muscles controlling the thoracic cavity relax, and the volume of the cavity is reduced.' This correctly describes the mechanism of typical mammalian exhalation.