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1.The graph shows the pattern of breathing in a person sitting at rest.

(a)(i)What is the name given to the volume of air labelled A? .......................................................................................................................... (1)

(ii)Explain how you would calculate the volume of air taken into the lungs in one minute. .......................................................................................................................... .......................................................................................................................... (1)

One way in which hospitals test how well the lungs are working is to measure the gas transfer factor. This is done by measuring the uptake of carbon monoxide from a single breath of air containing 0.3% carbon monoxide. (b)(i)By what process would carbon monoxide pass from the air in the alveoli to the blood in the lung capillaries? .......................................................................................................................... (1)

(ii)Suggest why carbon monoxide is used for this test.
.......................................................................................................................... .......................................................................................................................... .......................................................................................................................... .......................................................................................................................... (2)

(c)Interstitial lung disease is a disease in which the alveolar walls become thicker. Explain why the gas transfer factor would be low in a person who had interstitial lung disease. ..................................................................................................................................... ..................................................................................................................................... (1)

(Total 6 marks)

2.Table 1 shows the blood pressure in the left atrium, the left ventricle and the aorta at different stages in a cardiac cycle. These three parts of the circulatory system have been labelled A, B and C.

Table 1

(a)What is the evidence from the figures in Table 1 that part B is the ventricle? ..................................................................................................................................... ..................................................................................................................................... (1)

(b)(i)At 0.3 s, the atrioventricular valves are closed. Give the evidence from Table 1 which supports this statement.
.......................................................................................................................... .......................................................................................................................... (1)

(ii)For approximately how long is the valve between the left ventricle and the aorta open? Give the reason for your answer. .......................................................................................................................... .......................................................................................................................... .......................................................................................................................... (2)

(c)The figures in the third column of Table 1 show the changes in pressure in the left ventricle.
(i)Describe how the pressure in the left ventricle differs from that in the right ventricle.
.......................................................................................................................... (1)

(ii)Explain what causes this difference....
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