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Figure 10 shows the estimated blood flow through some parts of the body when a person is at rest and during exercise - Edexcel - GCSE Biology - Question 5 - 2018 - Paper 1
Question 5
Figure 10 shows the estimated blood flow through some parts of the body when a person is at rest and during exercise. | part of the body | estimated rate of... show full transcript
Worked Solution & Example Answer:Figure 10 shows the estimated blood flow through some parts of the body when a person is at rest and during exercise - Edexcel - GCSE Biology - Question 5 - 2018 - Paper 1
Step 1
Compare the rate of blood flow through the body when this person is at rest and during exercise.
Answer
The blood flow through the brain remains relatively constant, showing a slight decrease from 750 cm³ per minute at rest to 748 cm³ per minute during exercise. In contrast, the blood flow to the heart muscle significantly increases from 350 cm³ per minute at rest to 1150 cm³ per minute during exercise.
Additionally, the blood flow through the other muscles experiences a substantial increase from 1200 cm³ per minute at rest to 14,500 cm³ during exercise. However, the blood flow through the digestive system decreases markedly from 2500 cm³ per minute at rest to 1200 cm³ per minute during exercise.
Step 2
Explain why there is a change in the rate of blood flow through the digestive system during exercise.
Answer
During exercise, the body prioritizes blood flow to the muscles to meet increased oxygen and energy demands, leading to a significant increase in blood flow to the heart and other muscles. Consequently, blood flow is reduced to the digestive system, reflecting the body's need to redirect resources for physical activity and to allow for respiration and energy release in the muscles.