Hint
Hint
Describe the sequence of events during inhalation (breathing in) and exhalation (breathing out), focusing on muscle contractions, volume changes in the thorax, and resulting pressure changes.
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Answer
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Explanation
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Real World Context
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Answer
Complete Answer
Ventilation involves inhalation and exhalation. Inhalation occurs when external intercostal muscles and the diaphragm contract, increasing thoracic volume and decreasing lung pressure, causing air to enter. Exhalation occurs when these muscles relax (passive) or internal intercostals/abdominal muscles contract (active), decreasing thoracic volume and increasing lung pressure, forcing air out.
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Mark Scheme
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Answer Explanation
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Examiner Tips
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Common Errors