Explain how the circulatory and respiratory systems support a 400 metre sprint. (4 marks)
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- Breathing rate and depth increase sharply from the start of the sprint.
- This causes more oxygen to enter alveoli for gas exchange.
- As a result, oxygen-rich blood becomes available for circulation.
- This enables the heart to pump oxygenated blood to working muscles.
- Heart rate rises toward maximum because muscles demand more oxygen.
- This triggers blood vessel dilation in active leg muscles.
- Consequently, most blood flow is redirected to working muscles.
- These combined changes therefore deliver the oxygen needed for sprint energy production.
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- Breathing rate and depth increase sharply from the start of the sprint.
- This causes more oxygen to enter alveoli for gas exchange.
- As a result, oxygen-rich blood becomes available for circulation.
- This enables the heart to pump oxygenated blood to working muscles.
- Heart rate rises toward maximum because muscles demand more oxygen.
- This triggers blood vessel dilation in active leg muscles.
- Consequently, most blood flow is redirected to working muscles.
- These combined changes therefore deliver the oxygen needed for sprint energy production.