Worksheet B7.01 Heart beat In each of the pairs of statements below, one statement is right and one is wrong. Tick the correct one, and then explain what is wrong with the other one. 1 a The left side of the heart contracts before the right side of the heart. b Both sides of the heart contract simultaneously. .............................................................................................................................. .............................................................................................................................. .............................................................................................................................. 2 a When the left ventricle contracts, the bicuspid valve is forced closed by the pressure of the blood. b When the left ventricle contracts, the bicuspid valve closes itself to stop blood flowing the wrong way. .............................................................................................................................. .............................................................................................................................. .............................................................................................................................. 3 a The heart beats more quickly during exercise because you need to breathe faster. b The heart beats more quickly during exercise because the muscles need more oxygen. .............................................................................................................................. .............................................................................................................................. .............................................................................................................................. © Cambridge University Press 2017 4 a The wall of the left ventricle is thicker than the wall of the right ventricle because the left ventricle contains oxygenated blood. b The wall of the left ventricle is thicker than the wall of the right ventricle because the left ventricle needs to produce a higher pressure when the muscle contracts. .............................................................................................................................. .............................................................................................................................. .............................................................................................................................. 5 a The septum of the heart is important because it separates oxygenated blood from deoxygenated blood. b The septum of the heart is important because it separates high-pressure blood from low-pressure blood. .............................................................................................................................. .............................................................................................................................. .............................................................................................................................. 6 a Coronary heart disease is caused by blockage of the arteries that supply the heart muscle with oxygenated blood. b Coronary heart disease is caused by blockage of the arteries that supply the brain with oxygenated blood. .............................................................................................................................. .............................................................................................................................. .............................................................................................................................. © Cambridge University Press 2017
