Same chapter3 marksDifficulty: Medium
State three differences between inspired and expired air.
The Respiratory System
3 marksDifficulty: Medium
Describe the mechanism of inspiration.
Original Khojo Papers practice question — not from a past board paper.
Answer
The diaphragm contracts and flattens, and the external intercostal muscles contract to raise the ribs upwards and outwards. The volume of the thoracic cavity therefore increases and the pressure inside falls below atmospheric pressure, so air rushes into the lungs.
No citable source has been recorded for this record. Treat it as practice material, not as fact.
Explanation
Expiration is largely passive, the muscles relaxing and the elastic lungs recoiling.
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