CSGD Quiz 3 2005

1

A patient presents with a severe impairment in their ability to form new memories and recall recent events; however has childhood memories and implicit learning abilities intact. Which ONE of the following brain areas is most likely to be damaged?


  Prefrontal cortex.

  Amygdala.

  Primary visual cortex.

  Hippocampus.

  Thalamus.


This parallels the classic case of HM, who exhibited this exact form of anterograde amnesia following bilateral hippocampal resection.

2

Which ONE of the following statements regarding drugs of abuse is CORRECT?


  All drugs with abuse potential inhibit dopaminergic transmission in the nucleus accumbens.

  Chronic alcohol abuse leads to marked psychological dependence but little physical dependence.

  Cocaine causes marked psychological dependence, characterised by intense drug craving, without causing significant physical dependence.

  The active component of cannabis (∆9 -THC) is a serotonin (5-HT) receptor agonist that causes hallucinations.

  In chronic opioid users administration of methadone will initiate a withdrawal response.


A is incorrect: Dependence-producing drugs increase dopamine in the nucleus accumbens. B is incorrect: Physical dependence is very common with chronic alcohol abuse. C is correct: At least true in lower doses. D is incorrect: Cannabis acts on cannabinoid receptors (G-coupled, results in inhibition of adenylate cyclase). E is incorrect: Methadone is administered to prevent a withdrawal response.

3

Which ONE of the following statements about benzodiazepines is CORRECT?


  They are safe in combination with alcohol.

  They have no anticonvulsant activity.

  They decrease Cl- conductance in neurons.

  They increase the affinity of GABA for the GABA A receptor.

  They have no hangover effects.


A is incorrect: Their similar mechanisms of action mean that they may act synergistically. B is incorrect: They are used as anti-convulsants for epilespy treatment. C is incorrect: They enhance the action of GABA receptors, which in turn open Cl- channels and increase Cl- conductance. D is correct: They allosterically modulate GABA-A receptors, increasing their affinity for GABA. E is incorrect: May have similar withdrawal symptoms to alcohol.

4

Which ONE of the following statements about tricyclic anti-depressants is CORRECT?


  They can activate alpha-adrenoceptors.

  They can be cardiotoxic.

  They can activate histamine receptors.

  They can activate muscarinic receptors.

  They can inhibit monoamine oxidase.


Tricyclics tend to ANTAGONISE all of the listed receptors. MOAIs are a different class of anti-depressant, leaving only B as the correct answer.

5

Which ONE of the following changes is seen as part of the normal ageing process?


  Increased saliva production.

  Increased responsiveness to beta-adrenergic stimulation.

  Decreased haemoglobin level.

  Decreased melatonin level.

  Decreased cardiac output.


A is incorrect: Ageing is associated with decrease saliva production. B is incorrect: A decrease in responsiveness to β-adrenergic stimulation is observed, due primarily to a decrease in the number of β-adrenoceptors. C is incorrect: Haemoglobin levels tend to be unchanged. D is correct. E is incorrect: CO is generally maintained, although with a compensatory increase in SV due to changed preload and afterload conditions.

6

Which ONE of the following pharmacokinetic processes is largely unaffected by ageing?


  Absorption.

  Distribution.

  Liver metabolism.

  Renal excretion.

  First pass metabolism.


A is correct. B is incorrect: Distributional changes are seen as a result of changes in body composition. C is incorrect: Loss of liver reserve capacity is observed. D is incorrect: Decreased renal mass, blood flow, filtration and ability to concentrate urine is observed. E is incorrect: Phase I metabolism (first pass - oxidation) is impaired, phase II (conjugation) is often unaffected.

7

Which ONE of the following has NOT been demonstrated to improve medication outcomes in older people?


  Academic detailing to the prescriber.

  Direct mail-outs to patients.

  Provision of clear, written instructions.

  Pharmacist medication review.

  Use of compliance aids.


A is incorrect: Education of prescribers is important. B is correct: Presumably, many patients don't/can't read them, forget about them or ignore them entirely. C is incorrect: Clear instructions are shown to increase compliance. D is incorrect: Pharmacist review is an important part of rationalising polypharmacy. E is incorrect: This has been shown to help patients keep track of their medications.

8

Which ONE of the following maternal conditions during early pregnancy is not teratogenic?


  Maternal diabetes.

  Maternal smoking.

  Maternal phenylketonuria.

  Maternal alcohol ingestion of > 5 drinks per day.

  Maternal isotretinoin use.


Smoking is associated with underdevelopment, but not teratogenicity.

9

Mutations in which ONE of the following genes results in Treacher Collins Syndrome?


  TGF beta.

  Sonic Hedgehog.

  Integrin beta1.

  TCOF1.

  ZIC2.

10

Which ONE of the following screening tests or test combinations provides the best estimate of the fetal risk of Down Syndrome in a particular patient?


  Maternal serum screening (MSS) at 11 weeks of pregnancy.

  Ultrasound assessment of fetal nuchal fold thickness at 12 weeks of pregnancy.

  A combination of the tests indicated in both A. and B. above.

  Maternal serum screening at 16 weeks of pregnancy.

  Ultrasound assessment of the fetus at 18 weeks of pregnancy.


A is incorrect: First trimester serum screen tests PAPP-A and β-hCG - it is rarely performed alone. B is incorrect: Nuchal translucency ultrasound in the first trimester is not usually performed alone. C is correct: Combined, A and B detect around 85-90% of Down syndrome pregnancies. D is incorrect: The so-called triple or quadruple serum test (AFP, estriol, &beta-hCG and inhibin A) detects around 70-75% Down syndrome pregnancies (not as much as C) E is incorrect: Second trimester ultrasound is usually used to pick up physical defects such as neural tube defects and limb malformation. Its results are often equivocal for Down syndrome because of 'soft markers' (risk factors for chromosomal abnormalities are often not definitive).