Explain how the body adjusts ventilation during aerobic exercise. (4 marks)
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Sample Answer
- Ventilation rate increases immediately when aerobic exercise begins. This occurs because working muscles demand more oxygen for energy production.
- Breathing depth increases to maximise lung capacity. As a result, more oxygen enters the lungs with each breath, improving oxygen availability.
- Breathing frequency rises from rest to meet metabolic demands. This happens because the body needs to maintain adequate oxygen supply and carbon dioxide removal.
- Therefore, increased ventilation prevents acid-base imbalance in the blood. Higher breathing rates enable efficient removal of carbon dioxide produced during metabolism.
- Respiratory muscles work harder to support these changes. Consequently, the diaphragm and intercostal muscles contract more forcefully to facilitate air movement.
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Sample Answer
- Ventilation rate increases immediately when aerobic exercise begins. This occurs because working muscles demand more oxygen for energy production.
- Breathing depth increases to maximise lung capacity. As a result, more oxygen enters the lungs with each breath, improving oxygen availability.
- Breathing frequency rises from rest to meet metabolic demands. This happens because the body needs to maintain adequate oxygen supply and carbon dioxide removal.
- Therefore, increased ventilation prevents acid-base imbalance in the blood. Higher breathing rates enable efficient removal of carbon dioxide produced during metabolism.
- Respiratory muscles work harder to support these changes. Consequently, the diaphragm and intercostal muscles contract more forcefully to facilitate air movement.