NST and MVST Physiology                                                                                                                         Part 1B

 

Collected Neurobiology and Neurophysiology Tripos Questions

Medics are examined in Neurobiology in a single paper with 6/6 short-answer questions (7 minutes each) and 3/6 longer essays (45 minutes each);  such questions are marked respectively MS and M. Natural Scientists have a Paper 2 (Neurophysiology), with 4/7 45-minute essays.   These are marked N.  Vets have their own 3 hour paper, covering the whole year's work in Physiology, with 6 compulsory short answers (45 min) and a choice of 3/6 45-minute essays; questions of this type are marked V or VS.



 

Synapses, sensory transduction and processing


1.       Compare the mechanisms by which sensory receptor potentials and post-synaptic potentials are generated. (M)

2.       Discuss the mechanisms and functions of synaptic inhibition. (N,V,M)

3.       Discuss synaptic and non-synaptic mechanisms of communication between neurones. (M)

4.       Discuss the mechanisms by which information is integrated by the motor neurone.

5.       Describe the various types of input received by a motor neurone.  How are these integrated to determine the discharge of impulses in the axon? [V,N]

6.       How is the synaptic input to a central neurone transformed into a postsynaptic spike train? (N)

6.       A motor neurone receives a large number of afferent synapses.  How does their activity combine to determine the firing frequency of the motor neurone? (V)

7        In what ways do different neurotransmitters affect post-synaptic cells? (V,N)

8.       How may one neurone affect another in the short and the long term? (N)

9.       What kinds of neurotransmitters and neuropeptides occur in the central nervous system?  How do their effects at synapses differ?  Why might multiple kinds be useful? [N]

10.     Discuss, giving evidence, the chemical mechanisms by which central neurones communicate with one another, including different types of intracellular signal transduction. [M]

11.     To what extent has the identification of neurotransmitters at particular sites enabled us to understand the functions of the nervous system? (M)

12.     How may one neurone influence the activity of another? (V)

13.     What is synaptic plasticity, and how may it be controlled?  Describe its role in the development of the nervous system and in memory. (N)

14.       Discuss the changes in synaptic connectivity and efficacy which may occur in the mature nervous system.  How may such changes relate to learning and memory? (M)

15.     How may the efficiency of a synapse be altered, in the short term and long term?  How may such changes relate to learning and memory? (N)

16.     How does the central nervous system store and retrieve information? (M)

17.     How may the efficacy of synaptic transmission be modulated?  What is the functional significance of such changes? (M)

18.     What kinds of learning occur in the brain?  What is known of their neural mechanisms? (N)

19.     What are the mechanisms of long-term changes in synaptic strength? How might these changes contribute to the various forms of memory and learning, and to the consolidation of connections during neural development? (N)

20.     What determines the frequency of impulses in sensory nerves?

21.     Compare the mechanisms determining the generation of action potentials by the motor neurone and the Pacinian corpuscle. (V)

22.     Compare transduction mechanisms in sensory receptors.  What are the common principles?

23.    Compare and contrast the transduction mechanisms used by [typically three of the following receptor types:] tactile, auditory, olfactory, gustatory, visual. (M,V,N)

24.    Compare the mechanisms of transduction of mechanical stimuli by receptors in the skin and the cochlea. (N)

25.     Compare and contrast sensory transduction in olfactory receptors and photoreceptors in vertebrates. (N)

26.     How does adaptation occur in sensory systems?  What use is it? (N,V)

27.     Many sensory receptors respond preferentially to changing stimuli.  Why might this preference be beneficial?  How is it brought about? (M)

28.     Discuss the functions of lateral inhibition and adaptation. (M)

29.     How is the location of a sensory stimulus mapped in the central nervous system? (M)

30.     What may be the functions of the efferent control of sensory receptors and of descending pathways in sensory systems? (N)

31.     Discuss the efferent control of sense organs. (M)

32.     Give examples of the alteration of the sensitivity of sense organs by efferent nerves.  What purposes may be served by such control? (V)

33.     Discuss the specificity of sensory receptors, with examples drawn from at least two of the following: the skin; the olfactory epithelium; the cochlea; the retina.

34.     Compare and contrast the signal transduction mechanisms used in visual, olfactory and auditory receptors cells. (N)

35.     To what extent does the structure of sensory receptors correlate with their function?  (N)

36.     Compare the structure and function of hair cells in the cochlea and vestibular apparatus. (M)

37.     (Write concise notes on) Long term potentiation; transduction by olfactory receptors; glial cells; presynaptic inhibition; transduction in cochlear hair cells; G proteins in the nervous system; lateral inhibition; taste transduction; hair cells; olfactory transduction  (MS/NS/VS)


 

Cutaneous sense


1        How does pain differ from other senses?

2.       Describe how nociceptors transduce potentially-painful stimuli, and discuss how the resulting afferent information is modulated in the central nervous system. (N)

3        What is the evidence that there are separate neural pathways carrying information to the brain concerning pain and discriminative touch?  (M,V)

4        On what evidence is it believed that different cutaneous sensations arise from activity in different specialised receptors? (N)

5        Is the mechanism of pain perception essentially different from that of other cutaneous sensations?

6        Discuss the mechanisms that regulate the transmission of nociceptive information. (M,V)

7        The sensation of pain varies, depending on other stimuli impinging on the body and on emotional state.  Describe the mechanisms underlying this variation. (M)

8        Discuss the neural basis of perception of pain. (V)

9        (Write concise notes on) descending control of responses to noxious stimuli; descending control of pain; stimulus-induced analgesia. (MS); dermatomes (NS)

10      Discuss the coding of information from the skin, and its central analysis. [N]

11      The skin is bombarded with information, only some of which is important for the organism's survival.  What mechanisms discard information from the skin?

12.     Discuss the various cutaneous and central nervous mechanisms which would enable an animal to know that (a) it was in contact with a surface; (b) that the surface was rough; (c) that it was cold; (d) that it was liable to damage the skin. (V)

13.     What is known about the central organisation and the neuronal processing of the sensory information that is carried to the brain in the dorsal columns? (N)

 



Sensory feedback from muscles


1.       How far is it useful to separate the motor and sensory functions of the central nervous system?

2.       To what extent is the control of movement dependent on sensory information?

3.       How is sensory information used in movement? (M)

3.       What is the role of feedback in the control of movement?  Where in the central nervous system may it operate? (V)

5.       How is sensory information used in the control of limb movements? (M)

6.       How is information from muscle spindles and other proprioceptors used in the control of voluntary movements? (N)

7.       Compare the control of ballistic and guided movements.

8.       Compare the control of movement by external and internal (efference copy) feedback.  Give examples. (M)

9.       What problems does the motor system face in controlling movements? To what extent are these shared by all movements or specific to different types of movement? (M)

10.     What do muscle spindles do?

11.     Describe how muscle spindles are involved in the control of posture and movement. (N)

12.    Discuss the role of muscle spindles in the control of movement and posture. (V,N)

13.    Discuss the role of muscle spindles and other proprioceptors in the control of voluntary movement. (M)

14.     What roles do muscle spindles play in reflex and voluntary movement? (M)

15.     What use is made of sensory information in the control of  muscle length and tension?

16.     What are the roles of feedback mechanisms in the control of grasping and manipulative movements, such as reaching for and picking up a small object? (M)

17.     (Write concise notes on) efference copy  (MS)


 

Posture


1.       What sensory information is used in maintaining balance and posture? [V,N]

2.       How is posture maintained?

3.       What is the contribution of the vestibular system to maintaining an stable posture? (V)

4.       Why do we need a vestibular apparatus?

5.       How does the vestibular apparatus work, and how does vestibular information complement visual information in maintaining a stable posture? (N)

6.       Discuss the interactions of the vestibular and visual systems.

7.       Describe the reflex effects of rotation of the head.  What sensory mechanisms are responsible for the observed effects?

8.       What sensory mechanisms are involved in reaching out and picking up an object in the dark? (N)

9.       Give an account of the mechanisms of proprioception. [M]

10.     (Write concise notes on) gaze-holding eye movements; vestibulo-cerebellum; stimulus-induced nystagmus (MS); the semi-circular canals (VS)


 

Higher control of movement


1.       Describe the circuitry and functions of the basal ganglia. (M)

2.       Give an account of physiological experiments that throw light on the functions of either the cerebellum or a specified area of the cerebral cortex.

3.       How may the intrinsic and extrinsic connections of the cerebellum be related to its function? (M)

4.       What do studies of lesions of the cerebellum and lesions of the basal ganglia reveal about the role of these structures in motor control? (M)

5.       What can be learned about the control of movement by stimulating and recording from different parts of the central nervous system? (N)

6.       What is known about the functions of the cerebellum? (N)

7.       Discuss the relation between the basal ganglia, cerebellum and motor cortex in the control of movement. (M)

8.       Compare and contrast the roles of the basal ganglia and cerebellum in the control of movement. (V)

9.       What is known of how the cerebellum and basal ganglia interact with the motor cortex in the control of movement? [N]

10.     Compare and contrast the roles of cerebral cortex and cerebellum in the control of voluntary movement. [M]

11.     What evidence suggests that different motor areas in the cerebral cortex have different roles in the planning and control of voluntary movement? (N)

12.     What neural mechanisms are thought to be involved in the planning and initiation of a voluntary movement? (M)

13.     What is known about the planning and co-ordination of motor activities by the brain? (N)

14.     What observations have aided the understanding of the motor cortex? (V)

15.     What evidence would convince you that a particular part of the brain is involved in the control of movement?  Discuss with reference to the cerebellum. (N)

16.     Describe the roles of three of the following structures in the control of movement: (a) basal ganglia; (b) cerebellum; (c) motor cortex; (d) vestibular apparatus. (N)

17.     How has the study of the activity of neurones during movement contributed to an understanding of the neural control of movement? (N)

18.     (Write concise notes on) Parkinsonism; spasticity; motor disorders of the basal ganglia; corticospinal tract (MS/NS)


 

Special senses


1.       Compare and contrast photopic and scotopic vision.

2.       Why do we have both rods and cones? (N)

3.       Discuss the significance of convergence and divergence in the retinal processing of rod and cone signals. (M)

4.       Outline the visual processes that allow our vision to operate over a large luminance range. (N)

5.       How is the visual system able to function at widely varying levels of light intensity?  (N,V)

6.       In what ways can one quantify the performance of the eye?  What factors limit its performance? (M)

7.       What are believed to be the mechanisms of colour vision?  How can defects in it be explained?

8.       How may visual acuity be tested?  What factors influence it? (M)

9.       Discuss factors affecting the quality of the optical image on the retina.  To what extent does the quality limit visual acuity?

10.     How does the visual system cope with the conflicting demands of high absolute sensitivity and high spatial acuity? (M)

11.     What structural features of the retina help to explain visual acuity? (M)

12.     What factors limit visual acuity at different light levels?

13.     What factors determine whether a visual stimulus will be seen?

14.     Write a concise account of any two of the following: colour vision; visual acuity; dark adaptation; eye movements; pupillary reflexes. (V)

15.     How does the visual system process information about colour? (N)

16.     Describe the kinds of eye movement and their control.

17.     Why do we need eye movements?  How are they controlled?

18.     What neural mechanisms underlie colour vision? (N)

19.     Compare the synaptic mechanisms acting on a-motor neurones in the spinal cord with those acting on retinal bipolar cells. How do the bipolar cell synapses contribute to the extraction of important visual information from the retinal image? (N)

20.     Discuss how the response properties of neurones at successive levels of the visual system differ.  (N)

21.     What are the functions of signals from the eye to the lateral geniculate nucleus, to the hypothalamus and to the mid-brain? (V)

22.     What has been learnt about the processing of sensory information in general by recording from cells in visual cortex?

23.     How is the information from over 100 million photoreceptors encoded in an optic
nerve containing little more than a million axons? (M)

24.     Describe the response properties of cortical neurones responding to visual stimuli.  What part may such neurones play in the visual perception of objects? [N]

25.     How are different aspects of the visual and somatosensory worlds mapped and processed in the cerebral cortex? [M]

26.     What is the evidence for a columnar arrangement in the cerebral cortex? (M)

27.     Compare the ways in which the auditory and visual systems encode the direction and distance of an object. (N)

28.     How do animals use their eyes and ears to localise an object in space? [V,M]

29.     Which cues and mechanisms are used to locate the direction of a sound source?  What errors might arise when listening under water? [M]

30.     How do we detect depth in a visual image? (M)

31.     How is information from visual receptors processed in the retina?  Why should such processing occur? (V)

32.     Discuss the processing of information at different levels in the visual pathways. (M,N)

33.    How is the visual image represented and analysed within the cerebral cortex?  (V,N)

34.    Compare the coding of visual information by retinal ganglion cells with coding in the visual cortices. (M)

35.     Discuss the analysis of information by the auditory system.

36.     How does the auditory system analyse the frequencies in a sound? (N)

37.     Describe how the frequency and loudness of a tone are coded in the auditory nerve. Discuss those aspects of the code which can provide information about the location of a sound source in space. (N)

38.     How are sounds converted to patterns of firing in the auditory nerve? [N]

39.     What is meant by place and periodicity coding in the auditory system?  How are these codes used? (N)

40.     How are sounds analysed in the cochlea? (V)

41.     How are the pitch and loudness of a sound encoded in the auditory system?  (N)

42.     How does the auditory system analyse the frequency and intensity of a sound? (M,V)

43.     What features of auditory stimuli can be distinguished by animals?  How are they encoded at different levels of the auditory system? (N)

44.     Compare and contrast the analysis of frequency in hearing, and of colour in vision. (M)

45.     How is stimulus intensity encoded in sensory systems? Discuss with reference to cutaneous sensation and hearing. (V)

46.     What is known of the mechanisms of smell and taste?  Comment on the physiological significance of these senses.

47.     What is known of the mechanisms of taste and olfaction?  How is information from these senses processed in the brain? (V)

48.     Discuss the behavioural importance of the olfactory system.

50.     Compare the ways in which information is modified from receptor to cortex in different sensory systems.  (M)

51.     (Write concise notes on) colour-coding in the optic nerve; the basilar membrane;  localisation of sounds in space; the superior colliculus;(MS); olfactory bulb (NS)


 

Higher cortical and limbic function


1.       What is known of the neural mechanisms of (from several questions): motivation and emotion; memory and learning; speech and aphasia; sleep, arousal;  synaptic plasticity;  the hippocampus; hypothalamic control of feeding; procedural memory. (N,V,M)

2.       What are the central mechanisms which translate the perception of a life-threatening situation into a co-ordinated neuroendocrine and autonomic response preparing the organism for action? (M)

3.       Evaluate the evidence that distinct neural systems underlie different forms of memory. (M)

4.       Discuss the relative contribution of the amygdala and hippocampus to memory. (M)

5.       Discuss the insights into the neural basis of learning and memory provided by electrophysiological and lesion studies within the hippocampus and cerebellum. (M)

6.       To what extent can different parts of the limbic system be assigned different functions? (N)

7.       Has an understanding of the chemical anatomy of the reticular formation helped to explain some of its functions? (M)

8.       Describe the role of the brainstem reticular formation in the control of sensation and the control of sleep and consciousness. (N)

9.       Describe the organization of the brain's reticular or isodendritic core. What functions have been attributed to its diffuse projections? (M)

10.     Discuss the interactions of the brain stem and cerebral cortex during arousal and sleep. (M)

11.     Discuss the neural mechanisms involved in sleep and arousal. (N)

12.     How is the level of cortical arousal influenced by subcortical structures? (M)

13.     What is known of the neural control of attention and sleep? (N)

14.     What central mechanisms are concerned with responses to stressful events? (M)

15.     How does the central nervous system assess and respond to emotive stimuli? (M)

16.     What is known of the localisation of function in the cerebral cortex?  (N)

17.     What are the 'association areas' of the cerebral cortex?  What may be inferred about their function from damage to them? [M]

18.     Discuss the functional organisation of the association cortices. (M)

19.     Describe some of the evidence for the localisation of function in the cerebral cortex. How are functions distributed between the two hemispheres? (N)

20.     What methods can be used to determine the function of a particular part of the brain?  Illustrate by reference to the role of the cerebral cortex in the control of movement. (V)

21.     Contrast our understanding of the functions of primary sensory and association cortex. (N)

22.     What structural and functional features appear to be common to different areas of the neocortex?  Discuss both intrinsic organisation and afferent input.  (M)

23.     What do sensory areas of cerebral cortex do? (M)

24.     (Write concise notes on) the amygdala;  apraxia; the neglect syndrome; circadian rhythms (MS); the amygdala (the amygdaloid nuclei) (VS); Agnosia (MS); REM sleep (MS)


 

 Methods, Development and General


1.       Discuss the methods used for defining nervous connections within the central nervous system.

2.       Discuss the ways in which either the motor cortex or the visual cortex have been investigated.

3.       Discuss the experimental evidence for localisation of functions in association areas of cerebral cortex. (M)

4.       Discuss the localisation of function in the cerebral cortex. (N)

5.       Why is it difficult to investigate the functions of the limbic system? (M)

6.       What have studies of lesions in the human brain taught us about its normal function? (M)

7.       How is it thought that axons grow and navigate during development and regeneration?  How may these functions be impaired in the adult? [M]

8.       How does an axon grow?  Compare the processes of axonal regeneration in peripheral and central nervous system. [N]

9.       How do axons grow, and how do they establish maps within the brain? (N)

10.     How do developing axons find their way? (N)

11.     What is known about the factors controlling the growth of axons in development?  How does the process of regrowth after injury occur?  (V)

12.     Discuss the mechanisms of functional recovery in the damaged nervous system. (M)

13.     Compare and contrast axonal regeneration in the central and peripheral nervous system.  (N,V)

14.     Compare and contrast the events which follow damage to the central nervous system and peripheral nervous system.  (N)

15.     Write an account of the processes regulating neuronal axon growth and recovery from injury. (M)

16.     Write an essay on nerve regeneration. (V)

17.     How are the major regions and cell types of the central nervous system determined during development? (N)

18.     What factors govern the growth of axons and the establishment of synapses during development? (M)

19.     Describe how axons grow to their target tissues and form synapses. (N)

20.     What cellular and molecular processes enable growing axons to navigate to their destinations in the developing nervous system? (M)

21.     What is the blood-brain barrier?  Why is it important? (M)

22.     What rôles does calcium play in the nervous system? (M)

23.     (Write concise notes on) the function of neuronal growth cones; developmental neuronal cell death; cerebral blood flow; neural induction; arousal; axonal guidance; olfaction; the corpus callosum; the hippocampus; the blood-brain barrier; cerebrospinal fluid; the internal capsule (MS); neurogenesis; choroid plexus  (NS); Suprachiasmatic nucleus (MS)



RHSC January 2001