A patient is admitted to hospital after a brain injury. Doctors observe that the patient is having difficulty controlling their breathing rate and heart rate, but their memory and ability to speak appear to be unaffected. Explain which regions of the brain are likely to have been damaged and which regions are likely to be unaffected, referring to the functions of each region in your answer.
Written & reviewed by James Millett — Biology (Imperial College London), PGCE Science (University of Cambridge).
Model answer (5 marks)
The medulla oblongata, which lies in the brainstem, controls the involuntary functions of breathing and heart rate. Damage to this area would therefore explain the patient’s difficulty in regulating these autonomic functions.
The cerebrum, particularly the cerebral cortex, is responsible for higher‑level functions such as memory and language. Because the patient’s memory and speech are intact, the cerebrum must be unaffected by the injury.
The cerebellum, which coordinates movement, posture and balance, is not mentioned as being affected and is therefore likely to be undamaged as well.
The cerebrum, particularly the cerebral cortex, is responsible for higher‑level functions such as memory and language. Because the patient’s memory and speech are intact, the cerebrum must be unaffected by the injury.
The cerebellum, which coordinates movement, posture and balance, is not mentioned as being affected and is therefore likely to be undamaged as well.
Examiner tips
- Mention the medulla oblongata first and link it to breathing/heart rate. State that the cerebrum is intact because memory and speech are normal. Include the cerebellum as a separate, likely unaffected region.
- Use the exact terms "medulla oblongata", "cerebrum" and "cerebellum" as the mark scheme expects.
- Keep the answer concise – 5 marks can be earned with two short paragraphs.
Mark scheme (5 marks)
- The medulla oblongata controls breathing rate and/or heart rate (non-voluntary/autonomic functions)
- The medulla oblongata is the region that is damaged / affected by the injury
- The cerebrum / cerebral cortex is responsible for memory and/or language / speech
- The cerebrum / cerebral cortex is unaffected / undamaged because memory and speech are intact
- The cerebellum controls coordinated movement / posture / balance (and is not mentioned as affected, so likely undamaged OR correctly identified as separate from the affected functions)
Related
- All WJEC A-Level Biology (Wales) revision notes →
- How to answer a "Explain" question →
- Decode the mark scheme abbreviations →
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