Biology 9700 · AS & A Level · The gas exchange system

The gas exchange system — practice question

Peak Flow is used in hospitals to diagnose some lung diseases. It measures the greatest rate at which air can be breathed out of the lungs. How will the Peak Flow for a person with emphysema differ from that for a healthy person?

  • AIt falls as carbon monoxide reduces oxygen-carrying capacity of the blood.
  • BIt falls as elastic fibres are damaged in the alveoli.
  • CIt remains constant as the damage to the lungs does not affect the lung volume.
  • DIt rises as larger air spaces make it easier for the air to flow.

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