Environmental Effects on Body Systems | OCR A-Level Physical Education (H555)
Environmental Effects on Body Systems
- 44 questions
- 3 subtopics
- Component 01: Physiological factors affecting performance
- Component 01
Environmental Effects on Body Systems is examined in Component 01, Physiological factors affecting performance.
It covers altitude and oxygen delivery, acclimatisation and timing arrival at altitude and exercise in the heat and cardiovascular drift.
Sample questions from Environmental Effects on Body Systems
Answer each one closed book first, then open the answer.
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Altitude and oxygen delivery
Why is oxygen delivery to the muscles impaired at altitude?
Show the answer
Arterial pO₂ is reduced, so the gradient between the blood and the muscle is smaller. Less oxygen diffuses into the muscle for aerobic respiration. -
Altitude and oxygen delivery
Why does submaximal exercise feel harder at altitude?
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A given workload is a higher percentage of the reduced VO₂ max. Heart rate, ventilation and blood lactate are all higher than at sea level. -
Acclimatisation and timing arrival at altitude
How long does acclimatisation to altitude take?
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Some changes, such as raised ventilation, begin within days. A meaningful rise in red blood cells takes several weeks. -
Acclimatisation and timing arrival at altitude
How does plasma volume change during acclimatisation?
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Plasma volume falls in the first days at altitude, which concentrates the haemoglobin. Plasma volume recovers over the following weeks. -
Exercise in the heat and cardiovascular drift
Why is exercise in hot, humid conditions especially demanding?
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Humid air is already heavily loaded with water vapour, so sweat evaporates poorly. Heat is not lost effectively, so core temperature keeps rising. -
Exercise in the heat and cardiovascular drift
How does heat affect the respiratory system?
Show the answer
Hot, dry air and dehydration dry out the airways and can irritate them. The breathing frequency rises as metabolic demand and body temperature increase.
The 3 subtopics
One subtopic is one session. Work down the list.
| Subtopic | What it covers | Questions |
|---|---|---|
| Altitude and oxygen delivery | Barometric pressure and pO₂ at altitude, slower diffusion at the alveoli, lower haemoglobin saturation and VO₂ max, heart rate, stroke volume and ventilation on arrival, dehydration, and endurance and explosive events at Mexico City 1968. | 14 |
| Acclimatisation and timing arrival at altitude | Acclimatisation above about 2,400 m, the kidneys, EPO and red blood cells, how long it takes, arriving a day or two to three weeks before competing, altitude sickness, ventilation, plasma volume and fluid intake. | 14 |
| Exercise in the heat and cardiovascular drift | The hypothalamus and thermoreceptors, radiation, conduction, convection and evaporation, humidity, sweating and falling plasma volume, venous return and stroke volume, cardiovascular drift and how to reduce it, and early-morning marathons. | 16 |
How the guide is worked
Answering a question from memory stores it far better than reading the answer again. The guide runs that as a fixed procedure on one subtopic at a time, about twenty minutes a session.
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Step 1 · Closed book
Cover the answers. Work through one subtopic and write down what you can. Leave blanks where you have nothing.
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Step 2 · Open book
Go back to the top. Read each printed answer and write it out in full, including the ones you had right.
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Step 3 · Closed book again
Same questions, same order, from memory. The gap between pass one and pass three is the session result.
Read the full method, the return schedule and the research behind it.
Nearby topics
OCR A-Level Physical Education Active Recall Guide
Every topic, not just this one. 2,133 questions with their answers.