NEUROPHYSIOLOGY, SYNAPTIC PHARMACOLOGY AND ENDOCRINOLOGY

Transcription

1 UNIVERSITY OF EAST ANGLIA School of Pharmacy Main series UG Examination NEUROPHYSIOLOGY, SYNAPTIC PHARMACOLOGY AND ENDOCRINOLOGY PHA-5004Y Time allowed: 2 hours Part ONE Answer ALL questions. For each question, there is ONE correct answer. Use the answer grid provided for ALL your answers. Part TWO Answer THREE of the FOUR questions. Use a SEPARATE answer book for EACH question in Part TWO. Each question has the same value. The marks distribution is shown as a percentage for each section of each question. Answer ALL parts of each of the individual questions you select. The mark allocation for the paper is: Part ONE carries 40% of the total mark. Part TWO carries 60% of the total mark. You are advised to spend approximately 50 min on Part ONE, 70 min on Part TWO. The paper consists of 10 pages in total. The following is provided: Multiple choice answer grid. Dictionaries are not permitted in this examination. Notes are not permitted in this examination. Do not take this question paper out of the examinations room. Do not turn over until you are told to do so by the Invigilator. (PHA-5004Y) Module Contact: Dr Laszlo Fabian, PHA Copyright of the University of East Anglia Version 1

2 2 PART ONE Answer ALL questions. For each question, there is ONE correct answer. Use the answer grid provided for ALL your answers. 1. Which ONE of the following statements is INCORRECT regarding cranial nerves? There are 12 pairs of cranial nerves They originate from the brain stem They include the vagus nerve They exclusively innervate target organs in the head and neck They can contain efferent and afferent neurons 2. Which ONE of the following statements is correct when describing skeletal and smooth muscle contraction? An increase in calcium is essential for both smooth and skeletal muscle contraction Both smooth and skeletal muscle fibres have a striated appearance Troponin and tropomyosin hold actin filaments in place in smooth muscle fibres only Both smooth and skeletal muscle are controlled by alpha-motor neurons Thin filaments in both skeletal and smooth muscle are composed of myosin 3. During skeletal muscle contraction a series of molecular events occur. Which ONE of the following is INCORRECT? The Z discs move closer together as the sarcomere shortens A binding site for the myosin head on the actin filament is revealed ATP is hydrolysed to ADP Calmodulin plays a central role in activating a kinase The A band of the sarcomere (representing the myosin fibres) remains a constant length 4. Which ONE of the following is an example of a catecholamine neurotransmitter? Acetylcholine ATP Dopamine Glutamate Nitric oxide

3 3 5. Excitatory post-synaptic potentials (EPSPs) are usually the result of which ONE of the following? Increased Na + permeability Decreased Ca 2+ permeability Increased K + permeability Decreased Na + permeability Increased Cl - permeability 6. Which ONE of the following statements is correct regarding phasic receptors? They have a sustained receptor potential They frequently exhibit an off-response They adapt slowly They are important in detecting sustained stimuli They show no adaption 7. Aqueous humour is secreted by which ONE of the following parts of the eye? Cornea Iris Trabecular meshwork Ciliary body Lens 8. Which ONE of the following statements is correct regarding the rods in the retina? They mediate colour vision They are less sensitive to light than cones They enable high visual acuity They are concentrated in the fovea They are important in night vision 9. In the Organ of Corti, the vibration of which ONE of the following membranes initiates sound transduction? The basilar membrane The tectorial membrane The oval window membrane The tympanic membrane The vestibular membrane TURN OVER

4 4 10. Which ONE of the following is NOT a major function of the autonomic nervous system? Contraction and relaxation of smooth muscle Control of exocrine glands Control of cardiac function Regulation of energy metabolism Contraction of skeletal muscle 11. Which ONE of the following is correct regarding the sympathetic nervous system? It is characterised by short pre-ganglionic and long post-ganglionic neurons The neurotransmitter at the post-ganglionic neuron is acetylcholine It mediates rest-and-digest responses It causes contraction of skeletal muscle A major sympathetic nerve is the vagus nerve 12. Parasympathetic neurons have cell bodies in which regions of the spinal cord? The lumbar and thoracic regions The lumbar and cranial regions The thoracic and cranial regions The thoracic and sacral regions The cranial and sacral regions 13. Which ONE of the following is typically NOT a cholinergic neuron? α-motor neuron Pre-ganglionic sympathetic neuron Pre-ganglionic parasympathetic neuron Post-ganglionic sympathetic neuron Post-ganglionic parasympathetic neuron 14. Reserpine inhibits which ONE of the following? PKC COMT PLC MAO vmat

5 5 15. Which ONE of the following is NOT a potential side effect of β-blockers? Bradycardia Drowsiness Hypotension Hypertension Symptoms of heart failure 16. Which ONE of the following statements about noradrenaline reuptake is INCORRECT? Noradrenaline reuptake is important for terminating noradrenaline signalling The majority of noradrenaline is repackaged into vesicles Noradrenaline is absorbed by non-neuronal cells The extraneuronal monoamine transporter is important for the reuptake of noradrenaline into presynaptic cells vmat is important for the repackaging of noradrenaline into vesicles 17. Which ONE of the following molecules is the LEAST selective for β-adrenoceptors? 18. Which ONE of the following statements about muscarinic receptors is correct? They are stimulated by alkaloids from deadly nightshade They are antagonised by atropine They are stimulated by nicotine They are inhibited by curare They mediate the effects of acetylcholine at the neuromuscular junction TURN OVER

6 6 19. Ipratropium is used in treatment of asthma. What is its pharmacological target? β2-receptors α1-receptors Muscarinic receptors Nicotinic receptors β1-receptors 20. Which ONE of the following is NOT a symptom of atropine poisoning? Tachycardia Dilation of pupil Dry mouth Excitement, irritability Decreased temperature 21. Which ONE of the following statements is INCORRECT about muscarine? It is a naturally occurring alkaloid It causes smooth muscle contraction It is a depolarising ganglion blocker It acts at G protein-coupled receptors Its action is antagonised by atropine 22. Relating to nicotinic receptor structure, which ONE of the following statements is INCORRECT? All receptors have 5 subunits All contain γ-subunits The binding site for acetylcholine involves the α-subunit All contain at least 2 α-subunits The M2 domain of each subunit forms the channel pore 23. Which ONE of the following statements is CORRECT regarding botulinum toxin? It acts as a sympathomimetic It acts as a parasympathomimetic It inhibits the release of acetylcholine from nerve terminals It enhances the release of noradrenaline from nerve terminals It blocks voltage-gated Na + channels

7 7 24. In the treatment of glaucoma, which ONE of the following describes the mechanism of action of β-blockers? They cause constriction of the ciliary muscle They increase drainage of aqueous humour via the trabecular meshwork They increase drainage of aqueous humour via the uveoscleral pathway They cause dilation of the pupil They decrease secretion of aqueous humour 25. Treatment of a patient with molecule 1 will result in which ONE of the following? 1 A reduction in central and peripheral acetylcholine levels An increase in central acetylcholine levels An increase in central and peripheral acetylcholine levels A reduction in peripheral acetylcholine levels An increase in peripheral acetylcholine levels 26. The local anaesthetic tetracaine has an enhanced action due to which ONE of the following? tetracaine An electron donating substituent in the ortho position An electron donating substituent in the para position An electron withdrawing substituent in the para position An electron donating substituent in the meta position An electron withdrawing substituent in the ortho position TURN OVER

8 8 27. Which ONE of the following is correct regarding neuropeptides? They are synthesised at the axon terminal on demand They are exclusive to the gastro-intestinal tract Their action is terminated at the synapse by breakdown in the synaptic cleft They exclusively bind to adrenergic receptors They are usually co-released along with small neurotransmitters 28. Which ONE of the following statements regarding adenosine is INCORRECT? Adenosine acts on A1, A2 and A3 receptors Caffeine is an antagonist of adenosine receptors Adenosine is used clinically to stop cardiac conduction in supraventricular tachycardia Adenosine is generated by adenylate cyclase Adenosine uptake is blocked by dipyridamole allowing its action to be prolonged 29. Nitric oxide (NO) acts at which ONE of the following to mediate its effects in the post-synaptic cell? Adenylate cyclase G protein-coupled receptors Guanylate cyclase Ligand-gated ion channels Nuclear receptors 30. Which ONE of the following statements about the serotonin-selective reuptake transporter (SERT) is correct? It is located on post-synaptic neurons It is expressed by gut epithelial cells and platelets It internalises 5-HT through a receptor-mediated mechanism It is blocked by reserpine It is blocked by tetrabenazine END OF PART ONE

9 9 PART TWO Answer THREE of the FOUR questions. Use a SEPARATE answer book for EACH question. 31. Answer BOTH parts. (a) Describe how THREE different modalities of taste are detected by taste cells. [60%] (b) Compare and contrast the transduction of odorant molecules with the transduction of taste molecules. [40%] 32. Answer ALL parts (a) to (c). (a) (b) (c) Describe the pharmacological basis of non-depolarising and depolarising block of the neuromuscular junction. [30%] Giving your reasons, describe how increasing the concentration of acetylcholine at the synapse would affect each type of neuromuscular block. [20%] Decamethonium (2) is a long acting depolarising muscle relaxant. 2 Explain how you could alter the structure to prepare a non-depolarising muscle relaxant with a reduced duration of activity. Your answer should include chemical diagrams. [50%] TURN OVER

10 Answer ALL parts (a) to (c). (a) Describe the effects that the following events would have on membrane potential: (i) Opening of Na + channels (ii) Closing of K + channels [20%] (b) Define the terms excitatory post-synaptic potential and inhibitory post-synaptic potential. [20%] (c) Describe the processes involved in spatial and temporal summation. Explain how these contribute to neuronal integration. Use a diagram to illustrate your answer. [60%] 34. Answer BOTH parts. (a) Describe the types of signalling activated by α1 and α2 adrenoceptors. [50%] (b) Describe the pharmacological consequence of the following on the cardiovascular system: (i) An α1 adrenoceptor antagonist (ii) An α2 adrenoceptor agonist [50%] END OF PAPER

11 UNIVERSITY OF EAST ANGLIA School of Pharmacy Main Series UG Examination Registration Number PHA- 5004Y NEUROPHYSIOLOGY, SYNAPTIC PHARMACOLOGY AND ENDOCRINOLOGY Part ONE Answer Grid Question No. Answer Question No Answer Staff only No. correct: No. wrong: No. not attempted: Final: Signature and check signature: (PHA-5004Y)

12 School of Pharmacy Examination Feedback Summary Module Name Neurophysiology, synaptic pharmacology and endocrinology Module Code PHA-5004Y Year 2017/18 Overall marks Mean mark: 60.79% Max. mark 90.40% Min. mark: 19.83% Grade distribution: 1 st Fail 28.6% 24.7% 24.7% 15.6% 6.5% MCQ (Questions 1 to 30): Mean mark: 70.82% Max. mark : 100% Min. mark: 23.33% Comments: Question: 31 No. of attempts 58 Comments: Part (a) was well answered with the majority of students managing to list three modalities of taste and produce some detail about how the different signals are detected and transduced. Some students lacked details on the receptors/ion channels detecting different taste modalities and was reflected in the marks. In particular for sweet/bitter/umami tastes detail was lacking on the GPCR pathway to activate TRPM5 and cause ATP release acting on purinergic receptors on the sensory nerve. In part (b) students generally managed to find several examples of similarities and differences to compare and contrast taste signal transduction to smell signal transduction. Good answers included stating a difference/similarity and explaining the details involved. Question: 32 No. of attempts 40 Comments Overall, parts (a) and (b) were answered well, with most students having an understanding of depolarising and non-depolarising neuromuscular block. Some answers, however, lacked detail. Part (c) was poorly answered and in many cases not attempted, suggesting that students were question spotting and did not expect a chemistry question to come up. In addition, the largest proportion of students answered the question in a generic what would I change and why approach rather than addressing the specific material taught in lectures on this unit. A good answer would explain the binding interactions of a muscle relaxant, the difference between depolarising and non-depolarising muscle relaxants, an example of increased degradation (esters or Hoffman elimination) and an example of increased bulk to give antagonist properties. Either two diagrams (one for each modification) or a good diagram of atracurium were required. Question: 33 No. of attempts 62 Comments: This question required a clear understanding of how opening and closing of channels leads to change in membrane potential and how changes in membrane potential via EPSPs and IPSPs School of Pharmacy Summative exam feedback (V1) January 2013 Page 1 of 2

13 influence neuronal firing. Some people had a thorough and detailed understanding of this, but many did not, which is reflected in the marks. Some described the action potential in part (a), but the question is not asking for this it is asking simply to describe what would happen to membrane potential as a consequence of channel opening / closing. Remember when talking about ionic gradients to refer to electrochemical gradients, not concentration gradients. In part (c), most answers lacked detail and accurate descriptions of summation. Make sure diagrams are included if they are asked for in a question some did not include a diagram. Also make the diagrams as accurate as possible. Question: 34 No. of attempts 71 Comments: The question was designed for the students to 1) recall the material delivered in lectures and workshop and 2) to apply the knowledge and predict physiological consequences of these signalling pathways. Generally, the students answered the first part well and could obviously recall the information. However, the students generally struggled to predict the physiological consequences. Even when students correctly identified the consequence, their answer lacked the detail required to score strong marks. School of Pharmacy Summative exam feedback (V1) January 2013 Page 2 of 2