Date :... Class: A1&2 Time Allowed: 40Minutes Maximum Marks: 25

Transcription

1 1 loomfield Hall School 1 Test (Unit 9) Name :... Paper: iolog y Date :... lass: 1& Time llowed: 40Minutes Maximum Marks: 5 TKheory Section: [Total 16 Marks] Fig. 1.1 shows the changes in blood pressure in the left atrium, left ventricle and aorta during one complete contraction of the heart. It also shows a recording of the electrical activity of the heart Key: left atrium left ventricle aorta blood pressure /kpa electrical activity /mv time / s Fig. 1.1 (a) Name the source of the electrical activity in the heart....[1]

2 (b) Explain how the heart is coordinated so that the ventricle contracts after the atrium has contracted.... [4] (c) With reference to Fig. 1.1, calculate the heart rate in beats per minute. Show your working and express your answer to the nearest whole number. nswer =... beats min 1 [] (d) The pressure in the right ventricle is rarely higher than 4.0 kpa. Explain why the pressure in the right ventricle is much lower than that in the left ventricle....[] [Total: 9]

3 Fig..1 shows three stages in the cardiac cycle. 3 G H 0.1 s 0.4 s 0.3 s F K Fig..1 J

4 4 omplete the table to show what is happening to the following parts of the left side of the heart at each of the stages, H, J and K as shown in Fig..1: left atrium left ventricle aortic valve. stage left atrium left ventricle atrioventricular valve aortic valve H contracts to force blood into left ventricle open closed J closed... K relaxes and fills with blood from left atrium open... [6] [Total: 6]

5 1 MQ SETION: [Total 10 Marks] In the mammalian heart, which structure is the pacemaker? atrioventricular node Purkyne (Purkinje) fibres bundle of His D sinoatrial node The table shows changes occurring in the body. Which combination would cause the greatest rise in cardiac output? 5 carbon dioxide frequency of aortic blood blood pressure in concentration impulses in the pressure the vena cava of the blood vagus nerve decrease no change increase no change decrease no change no change increase no change decrease increase no change D no change decrease no change increase Which chamber of the heart shows the greatest pressure changes during one cardiac cycle? left atrium right atrium left ventricle D right ventricle Which event occurs during contraction of the left ventricle? The bicuspid valve opens. The semilunar valve in the aorta closes. The pressure in the left atrium becomes greater than the pressure in the left ventricle. D The pressure in the left ventricle becomes greater than the pressure in the aorta. Which structures are found in both arteries and capillaries? collagen fibres endothelial cells elastic fibres D smooth muscle cells What is the function of the Purkyne (Purkinje) tissue in the mammalian heart? D to conduct a wave of electrical excitation over the atria to conduct a wave of electrical excitation over the ventricles to reduce the spontaneous contraction rate of the heart to separate oxygenated blood from deoxygenated blood

6 7 6 The diagram shows pressure changes in the left side of the heart during the cardiac cycle. 0 pressure / kpa 10 X key left ventricle aorta left atrium What happens at X? time / s atrioventricular valves close semilunar valves close atrioventricular valves open D semilunar valves open Which feature enables the aorta to withstand high pressure at ventricular systole? D collagen fibres and elastin fibres collagen fibres and semilunar valves elastin fibres and large lumen semilunar valves and smooth muscle 9 The table summarises some characteristics of arteries, veins and capillaries. characteristics arteries veins capillaries 1 blood pressure high low low lumen wide narrow narrow 3 wall thick thin single cell Which lines in the table are correct? 1 and only 1 and 3 only and 3 only D 1, and 3

7 7 10 elow are correct statements comparing blood, and in a bed. W lacks large plasma proteins and red blood cells and has a higher water potential than Z. X is at a lower pressure than Y and contains red blood cells and large plasma proteins. Y is at a higher pressure than W and contains red blood cells and large plasma proteins. Z is at a lower pressure than Y and lacks red blood cells. Which correctly identifies W, X, Y and Z? W X Y Z D MQ nswer Sheet 1 D D 3 D 4 D 5 D 6 D 7 D 8 D 9 D 10 D