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The diagram shows a human heart - Edexcel - GCSE Biology - Question 5 - 2012 - Paper 1
Question 5
The diagram shows a human heart. (a) (i) Draw an arrow onto the diagram to show where oxygenated blood enters the heart. (ii) Suggest how the blood flowing through... show full transcript
Worked Solution & Example Answer:The diagram shows a human heart - Edexcel - GCSE Biology - Question 5 - 2012 - Paper 1
Step 1
Step 2
Suggest how the blood flowing through the pulmonary artery would be different from the blood flowing through the aorta.
Answer
The blood in the pulmonary artery is deoxygenated, meaning it carries less oxygen compared to the oxygenated blood flowing through the aorta. Furthermore, the blood pressure in the pulmonary artery is lower than that in the aorta, as the aorta needs to distribute blood throughout the body.
Step 3
Describe the role of the valve labelled on the diagram.
Answer
The role of the valve labelled on the diagram is to prevent the backflow of blood. It ensures that blood flows in one direction, either from the atrium to the ventricle or from the ventricle to the pulmonary artery/aorta, maintaining efficient circulation.
Step 4
Step 5
Explain the effects that a reduced cardiac output would have on the muscle cells of an athlete.
Answer
A reduced cardiac output limits the amount of oxygenated blood reaching the muscle cells of an athlete, which adversely affects their performance. This lack of sufficient oxygen results in a decreased capacity for aerobic respiration, leading to a buildup of lactic acid, fatigue, and a reduced ability to sustain high levels of activity. Consequently, muscle cells may not function optimally, limiting endurance and strength during physical exertion.