The human brain and imagingEdexcel International A Level Biology: Subtopic test

1. 1
   After a car accident a patient has jerky, uncoordinated limb movements and cannot keep her balance, although her speech and understanding are normal. Paramedics also monitor her breathing and heart rate because her brain may have been injured.

   (a)

   Which part of the brain is most likely to have been damaged?

   [1 mark]

   • AMedulla oblongata
   • BHypothalamus
   • CPituitary gland
   • DCerebellum

   (b)

   Which part of the brain controls the rate of breathing and the heart rate?

   [1 mark]

   • AMedulla oblongata
   • BCerebellum
   • CPituitary gland
   • DCerebral hemispheres

   (c)

   Suggest why damage to this part of the brain causes uncoordinated movement but leaves speech and understanding unaffected.

   [2 marks]

   Total for question 1: 4 marks

2. 2
   A patient with damage to the pituitary gland produces very large volumes of dilute urine, and a neurologist is investigating how the brain and pituitary control the water content of the body.

   (a)

   Which part of the brain controls the secretion of hormones by the pituitary gland?

   [1 mark]

   • ACerebellum
   • BHypothalamus
   • CMedulla oblongata
   • DCerebral hemispheres

   (b)

   Which of these is a function of the hypothalamus?

   [1 mark]

   • ACoordination of balance
   • BControl of the breathing rate
   • CMonitoring the water potential of the blood and the body temperature
   • DInterpretation of language

   (c)

   Suggest why damage to the pituitary gland causes the production of large volumes of dilute urine.

   [2 marks]

   Total for question 2: 4 marks

3. 3
   A hospital has CT, MRI, fMRI and PET scanners. One patient arrives with a suspected skull fracture and bleeding after a fall. Separately, a research team wants to find which regions of the cerebral hemispheres are most active while volunteers solve a puzzle, and needs to scan each volunteer several times.

   (a)

   Choose the most suitable scan for the patient and for the research team, giving one reason for the patient's choice and two reasons for the research team's choice.

   [3 marks]

   (b)

   Explain how a PET scan could show which regions of the cerebral hemispheres are active, and give one limitation of using PET for this research.

   [4 marks]

   Total for question 3: 7 marks

4. 4
   Parkinson's disease and depression are both linked to abnormal activity of neurotransmitters in the brain. Doctors use brain imaging to investigate both conditions, and drug companies are developing new treatments.

   (a)

   Explain how the loss of dopamine causes the symptoms of Parkinson's disease, and how scans can be used in its diagnosis and in research.

   [6 marks]

   (b)

   Explain how a drug that inhibits the reuptake of serotonin could relieve depression, and discuss what must be done before such a drug is used to treat patients.

   [6 marks]

   Total for question 4: 12 marks

End of questions