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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 blood flow... 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, decreasing slightly from 750 cm³/min to 748 cm³/min during exercise.
In contrast, the heart muscle receives significantly more blood flow during exercise, increasing from 350 cm³/min to 1150 cm³/min.
There is a marked increase in blood flow to the other muscles, rising dramatically from 1200 cm³/min at rest to 14500 cm³/min during exercise.
However, the digestive system experiences a decrease in blood flow from 2500 cm³/min at rest to 2200 cm³/min during exercise.
Step 2
Explain why there is a change in the rate of blood flow through the digestive system during exercise.
Answer
The change in blood flow to the digestive system during exercise is due to the body's need to prioritize blood supply to the muscles that are actively engaged in physical activity. During exercise, there is increased blood flow to the muscles to facilitate respiration and energy production. As a result, the blood flow to the digestive system is reduced to accommodate this need.