Practise CAIE AS Biology heart questions by labelling chambers and valves, comparing wall thickness, and tracing pressure changes and electrical conduction across the cardiac cycle.
The diagram shows an anterior view of a vertical section through the human heart.
Which row shows the correct labels for the diagram?
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2
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4
aorta
atrioventricular valve
semilunar valve
pulmonary artery
pulmonary vein
semilunar valve
atrioventricular valve
pulmonary vein
pulmonary artery
semilunar valve
atrioventricular valve
vena cava
pulmonary vein
atrioventricular valve
semilunar valve
vena cava
Aortic stenosis is a heart valve disorder in which the aortic semilunar valve opening is narrow.
Which effect could aortic stenosis have on heart structure and function?
The cardiac muscle of the left ventricle wall is thinned by blood leaking out of the left ventricle during ventricular diastole.
There is less cardiac muscle in the left ventricle and reduced diastolic blood pressure, caused by the smaller blood volume entering the left atrium.
The tendons of the heart valves are weakened by blood being forced back through the left atrioventricular valve into the left atrium.
The wall of the left ventricle thickens, leading to an enlarged heart and inability to relax and fill completely during diastole.
The diagram shows pressure changes during two cardiac cycles.
Which arrow indicates atrial systole?