3. The most common excitatory transmitter in the central nervous system is: A. acetylcholine B. glutamate C. glycine D. serotonin E.

Transcription

1 1. All of the following statements about the axon shaft are true EXCEPT: A. axonal diameter is inversely proportional to conduction velocity B. ion channels are clustered at nodes of Ranvier C. it contains parallel arrays of neurofilaments and microtubules D. it may be ensheathed by nonmyelinating glia 2. Which of the following statements about astrocytes is TRUE: A. they form myelin in the central nervous system B. they produce large amounts of collagen in the central nervous system C. they participate in forming the blood-brain barrier D. they can be phagocytic in function E. they are involved in neuronophagia 3. The most common excitatory transmitter in the central nervous system is: A. acetylcholine B. glutamate C. glycine D. serotonin E. GABA 4. Transmitters are inactivated at synapses by all of the following mechanisms EXCEPT: A. diffusion out of the synaptic gap B. enzymatic breakdown C. re-uptake by the presynaptic terminal D. uptake by astrocytes that ensheath the synapse E. uptake by oligodendrocytes 5. All of the following statements about metabotropic receptors are true EXCEPT: A. they contain an ion channel B. they use the different a, b, g subunits C. they contain a ligand binding site D. they are often linked to G-proteins 6. The most vulnerable location where blockage of CFS flow results in hydrocephalus is: A. interventricular foramen of Monro B. choroid plexus C. cerebral aqueduct D. lateral foramen of Luschka E. cisterna magna 7. The decussation (crossing) of the medial lemniscus (internal arcuate fibers) is located in the: A. spinal cord B. medulla C. pons D. midbrain E. diencephalon 1

2 8. Axons of which of the following tracts cross from one side of the nervous system to the other: A. ascending root of V B. fasciculus cuneatus C. dorsolateral fasciculus D. ventral trigeminothalamic tract E. spinal tract of V 9. Cell bodies that give rise to the lateral spinothalamic tract axons are located in the: A. apical region of the dorsal horn B. substantia gelatinosa C. nucleus proprius D. all of the above E. A and C 10. Chronic pain is transmitted more slowly than acute pain because chronic pain signals are carried by: A. C fibers B. myelinated axons C. A delta fibers D. B fibers E. larger diameter axons 11. The spinal trigeminal tract has its origin from neurons located in the: A. trigeminal ganglion B. spinal trigeminal nucleus C. chief sensory nucleus of V D. substantia gelatinosa of C1 to C3 E. mesencephalic nucleus of V 12. Which of the following statements about myelin is TRUE: A. astrocytes form myelin around axons in the peripheral nervous system B. myelinated axons have smaller Length Constants compared to unmyelinated axons C. in the central nervous system, myelin is formed by oligodendrocytes D. schwann cells form the epineurium around peripheral nerves E. ion channels are distributed uniformly along myelinated axons 13. Which of the following statements about neurons is TRUE: A. dendrites are usually unmyelinated B. when an axon reaches its target, it generally synapses without branching C. neuronal cell bodies contain little rough endoplasmic reticulum D. axonal transport is necessary only for neurons with small diameter axons E. unmyelinated axons are not ensheathed by glia 14. Which of the following statements about synaptic events is TRUE: A. presynaptic terminals usually do not contain mitochondria B. calcium influx is not essential for synaptic transmission C. transmitters in the synaptic gap can be inactivated by diffusion D. sodium influx is essential for transmitter release E. a major excitatory transmitter is GABA 2

3 15. Which of the following statements about graded synaptic potentials is TRUE: A. they have a threshold B. they are slow events compared to action potentials C. they are only excitatory D. they result from transmitter binding to metabotropic receptors E. they do not decay with distance along the dendrite 16. All of the following statements about glutamate receptors are true EXCEPT: A. calcium ions normally block this channel B. they can be ionotropic or metabotropic in type C. activation of the NMDA receptor alone causes little voltage change D. current through NMDA receptors is greater when the neuron is already depolarized E. activation of the NMDA receptor can cause ionic current carried by calcium ions 17. In contrast to ionotropic receptors, metabotropic receptors: A. require more transmitter for an effect B. act more quickly in producing an effect C. contain a channel that allows ion flow D. produce a response that greatly outlasts binding to the receptor E. activate chemical intermediates with short lifetimes in the neuron 18. The epidural space around the brain: A. Is a potential space located between the periosteum and the dura mater B. Is a potential space that may fill with blood and cause hydrocephalus C. Contains cerebrospinal fluid D. Is a potential space located between the dura and arachnoid mater E. A and C 19. Which of the following is NOT TRUE? A. There is choroid plexus is each ventricle. B. CSF is resorbed into the venous sinuses from arachnoid granulations. C. CSF is continually produced and resorbed; it turns over about 5 times/ day D. Communicating hydrocephalus results from blockage of the cerebral aqueduct E. Increased CSF pressure can cause papilledema 20. Which of the following are axons of first order sensory neurons: A. ventral trigeminothalamic tract B. medial lemniscus C. ventral white commissure D. internal arcuate fibers E. dorsolateral fasciculus 21. Which of the following statements is NOT TRUE about the pathway that transmits information about the emotional aspects of pain: A. there are multiple synapses between the spinal cord and thalamus B. it is mediated by type C fibers C. this pathway terminates in the cingulate gyrus 3

4 D. this pathway synapses in the ventral posterior lateral thalamic nucleus E. this pathway is part of the anterolateral system (ALS) 22. The dorsolateral fasciculus contains axons that will: A. cross to the opposite side of the CNS B. ascend to the medulla before synapsing C. synapse in laminae I and V D. enter the ventral white commissure E. mediate proprioceptive sensation 23. When you injure yourself, you immediately feel a sharp pain from the site of injury followed by a throbbing painful sensation. Which of the following statements about this is FALSE: A. the immediate pain sensation is carried by Ad fibers B. the immediate pain sensation travels via the lateral spinothalamic pathway C. the throbbing pain sensation travels via the spinoreticulothalamic pathway D. the throbbing pain sensation is mediated by the ventroposterior lateral nucleus E. the immediate pain sensation is localized on the body by the postcentral gyrus 24. All of the following contain axons or cell bodies of second-order sensory neurons EXCEPT: A. medial lemniscus B. fasciculus cuneatus C. internal arcuate fibers D. nucleus gracilis E. anterior white commissure 25. At which of the following locations is the somatotopic orientation of the body in the medial lemniscus represented as upper body is dorsomedial and lower body is ventrolateral: A. midbrain B. rostral pons C. caudal pons D. rostral medulla E. cortex 26. Which statement is NOT true about the mesencephalic nucleus of V: A. it contains the cell bodies of second-order sensory neurons B. it is involved in the jaw-jerk reflex C. axons of its neurons travel in the trigeminal nerve D. axons of its neurons synapse in the trigeminal motor nucleus E. it contains pseudounipolar neurons 27. Information about tactile sensation from the chin is carried by all of the following EXCEPT: A. chief sensory nucleus of V B. mandibular division of cranial nerve V C. mesencephalic nucleus D. ventral trigeminothalamic tract E. VPM 4

5 28. Cell bodies in the brainstem that send axons to spinal cord to inhibit pain transmission are located in: A. periaqueductal gray B. nucleus raphe magnus C. association cortex D. cingulate cortex E. all of the above 29. Which of the following statements about sensory systems is TRUE: A. axons mediating touch cross the nervous system in the cervical spinal cord B. a lesion of the ventral white commissure damages pain fibers bilaterally C. touch information from the upper legs travels in fasciculus cuneatus D. first order neurons synapse onto second order neurons in the dorsal root ganglion E. the VPL of thalamus is involved in emotional aspects of pain 30. The majority of the largest diameter nerve fibers in the dorsal roots synapse in: A. marginal zone of the spinal cord B. medial lemniscus C. intralaminar nuclei D. VPL E. nucleus cuneatus 31. At which of the following locations is the somatotopic orientation of the body for tactile information represented as upper body is lateral and lower body is medial: A. rostral pons B. caudal pons C. cervical region of spinal cord D. rostral medulla E. caudal midbrain 32. Which of he following statements about the trigeminal system is TRUE: A. tactile sensation for the face is mediated by VPL but pain is mediated by VPM B. trigeminal pathways terminate on the posterior portion of the paracentral lobule C. regions at the back of the face are represented caudally in the spinal trigeminal nucleus D. trigeminal neuralgia is thought to be caused by a lesion in the ventral trigeminothalamic tract E. axons of second order neurons mediating pain are located in the spinal trigeminal tract 33. The pathway involved in reflex contraction of the lower jaw when the chin is tapped downward utilizes cell bodies of first order sensory neurons located in the: A. trigeminal ganglion B. spinal trigeminal nucleus C. dorsal root ganglion D. mesencephalic nucleus of V E. facial nucleus 34. Which of the following statements about CNS development is TRUE: A. the most likely time for a neural tube defect is months 3-4 of gestation B. the Arnold Chiari malformation is often accompanied by a meningomyelocele 5

6 C. the thalamus develops from the telencephalic embryonic compartment D. rostral defects in neural tube closure result in microgyria E. A and C are both correct 35. The process of proliferation and migration of differentiating neuroepithelial cells is associated with all of the following EXCEPT: A. anencephaly B. formation of cortical layers C. lissencephaly D. polymicrogyria E. shape of the cerebral hemispheres 36. Which type of glial cell participates in removing neurotransmitter from the synaptic cleft in the CNS: A. microglia B. schwann cell C. astrocyte D. oligodendrocyte E. ependymal cell 37. The myelin sheath around axons: A. can be formed by schwann cells B. is a continuous covering from cell body to terminals C. decreases the electrical capacitance of the axon D. A, B, C are all correct E. only A and C are correct 38. Which of the following statements about subdural hematomas is FALSE: A. they result from rupture of an artery B. resulting symptoms may be delayed by weeks or months C. they enlarge gradually as scarring and recurrent bleeding occurs D. they are usually caused by head trauma E. bleeding occurs slowly 39. Pyridostigmine bromide (Mestinon) improves strength in patients with myasthenia gravis by: A. reducing the acetylcholine antibody titer B. increasing presynaptic release of acetylcholine C. inhibiting acetylcholinesterase D. increasing the number of functional post-synaptic acetylcholine receptors E. slowing degradation of acetylcholine receptors 40. Which of the following statements about hydrocephalus is FALSE: A. it can result from a tumor in the cerebral aqueduct B. it can result from impaired reabsorbtion of CSF C. it often causes paplledema D. symptoms may include headache, nausea, and vomiting E. it is always associated with an increase in CSF pressure 41. Which statement below regarding brain edema is TRUE? 6

7 A. the ventricles are enlarged B. the brain weight is increased C. in vasogenic edema, the fluid is restricted to the cells (intracellular) D. it is the hallmark of brain atrophy E. a major cause of edema is intracranial herniation (i.e. transtentorial) 42. Which of the following statements about degeneration and regeneration is TRUE: A. gliosis is an area of fibrosis in the CNS containing abundant collagen B. in the CNS, astrocytes release extracellular matrix molecules to promote axonal growth C. wallerian degeneration involves death of the schwann cells in the distal nerve D. the time for functional recovery of a peripheral nerve is about 1mm/day E. chromatolysis involves degeneration of the myelin sheath in a damaged nerve 43. Concerning glutamate receptors, which statement is FALSE: A. there are both ionotropic and metabotropic types B. Ca ions normally block the pore of the NMDA receptor C. the EPSP from an NMDA receptor can be enhanced significantly by activation of another excitatory synapse just before the NMDA activation D. AMPA and NMDA are ionotropic receptors E. glutamate in the synaptic cleft can affect both presynaptic and postsynaptic membranes 44. Which statement about cells in nucleus cuneatus is FALSE: A. convergence of inputs allows them to respond better to larger stimuli B. it receives sensory information from the upper body C. inhibitory interneurons allow some cells to respond better to small stimuli than to large stimuli D. its axons cross to the opposite side of the nervous system E. it is located in the spinal cord 45. Which of the following events is associated with an increase in pain perception? A. decreased bradykinin synthesis B. decreased prostaglandin production C. inhibition of substance P receptors on mast cells D. decreased concentrations of voltage-sensitive sodium channels at neuromas E. decrease in ph of the tissue. 46. The corneal reflex is mediated by all of the following EXCEPT: A. spinal trigeminal tract B. trigeminal ganglion C. motor nucleus of CN VII D. ophthalmic division of CN V E. ventral trigeminothalamic tract 47. Descending pathways that modulate pain involve all of the following EXCEPT: A. ventral posterior lateral nucleus (VPL) B. periaqueductal gray 7

8 C. serotonin D. substantia gelatinosa E. nucleus raphe magnus 48. Type Ad fibers are associated with which of the following structures: A. spinoreticulo-thalamic tract B. nucleus gracilis C. VPL D. intralaminar thalamic nuclei E. internal arcuate fibers 49. In which of the following locations are tactile sensory fibers representing the upper body positioned dorsal and tactile sensory fibers for the lower body positioned ventral: A. caudal midbrain B. rostral medulla C. cervical area of spinal cord D. rostral pons E. thalamus 50. All of the following headache patients require urgent evaluation EXCEPT: A. patient with a severe headache every day for the past five years B. patient presenting with "the worst headache of my life" C. elderly patient with new onset headaches of mild-moderate severity D. patient with associated fever and confusion E. patient with papilledema 51. Opioid agonist-antagonists like pentazocine: A. have analgesic effects that increase linearly with drug concentration B. have high potential for drug addiction. C. are recommended for use in patients who have coronary artery disease D. are not effective for postoperative analgesia. E. can precipitate withdrawal effects in addicts. 1. A 11. A 21. D 31. C 41. B 51. E 2. C 12. C 22. C 32. C 42. D 3. B 13. A 23. D 33. D 43. B 4. E 14. C 24. B 34. B 44. E 5. A 15. B 25. C 35. A 45. E 6. C 16. A 26. A 36. C 46. E 7. B 17. D 27. C 37. E 37. A 8. D 18. A 28. B 38. A 48. C 9. E 19. D 29. B 39. C 49. B 10. A 20. E 30. E 40. E 50. A 8

9 VISUAL SYSTEM 1. The following reflexes are paired with structures that form part of the reflex pathway. Which one is NOT correct: A. jaw jerk reflex : mesensephalic root B. dark adaptation : sympathetic trunk C. pupillary light reflex : brachium of superior colliculus D. corneal reflex : optic tract E. accommodation : optic radiations 2. Which of the following statements about the eye is FALSE: A. cones are concentrated in the fovea B. when the ciliary muscle contracts, the lens becomes more round C. a patient with hydrocephalus would most likely also have papilledema D. cones are very sensitive to dim illumination E. rods are concentrated in the periphery of the retina 3. Which of the following is NOT involved in the pathway for voluntary horizontal conjugate gaze: A. brachium of the superior colliculus B. cranial nerve III C. MLF D. paramedian pontine reticular formation E. cranial nerve VI 4. Choose the best answer concerning the retina. A. When light strikes a rod photoreceptor, rhodopsin channels open and admit Na + to the outer segment. B. In very dim illumination (e.g., moonlight), cone photoreceptors are hyperpolarized. C. ON-center ganglion cells fire more action potentials as the stimulus becomes larger and larger, until it fills the whole receptive field. D. Ganglion cells with transient responses are common in the retinal periphery. E. Both A and B are true. 5. Choose the best answer concerning the normal development of the visual system. A. All layers of the cortex contain some binocular cells at birth. B. Axons from the lateral geniculate to the visual cortex make and break synaptic connections both before and after birth. C. NMDA receptors contribute to stabilization of active synapses by admitting glutamate into dendrites of cortical cells. D. Prior to birth, ganglion cells in both eyes fire simultaneously. E. Both A and B are true. 9

10 6. Choose the best answer concerning the effects of a severe cataract in the left eye at birth. A. The cataract should be removed before the axons from the eye first grow into the lateral geniculate. B. If the cataract is removed when the child is between 1 and 2 years old, binocular vision will eventually be normal. C. Axons from the lateral geniculate on the right side of the brain will eventually occupy much more of layer 4 of the cortex than will axons from the lateral geniculate on the left side of the brain. D. If the cataract is not removed until the child is 10 years old, most of the cells outside layer 4 of the cortex will respond only to visual input from the right eye. E. If the cataract is never removed, axons from left eye will innervate fewer laminae of the lateral geniculate than normal. 7. The Loop of Meyer: A. Is found in the optic nerve B. Contains fibers representing the upper retina C. Is found in the temporal lobe D. Is found in the parietal lobe E. Is found on the ventral surface of the cerebral hemisphere 8. Which of the following regarding the aqueous humor system is NOT TRUE? A. The vitreous body produces aqueous humor. B. An excess of aqueous humor results in glaucoma C. Aqueous humor is resorbed into the venous system through the Canal of Schlemm D. The pupil allows aqueous humor to enter the anterior chamber of the eye E. It is actively secreted and turns over several times a day. Matching: A patient is instructed to "look right". For Left Right each lesion described below, select the resulting appearance of the patient's eyes. A 9. Lesion of the left MLF 10. Lesion of the right CN VI B C D 10

11 11. Which of the following is NOT TRUE of Horner's syndrome? A. It is caused by interruption of the sympathetic innervation to the head. B. Lesion involving the superior cervical ganglion results in ipsilateral Horner's syndrome. C. A lesion of parasympathetic fibers in the carotid plexus would result in ipsilateral Horner's syndrome. D. A lesion of the ciliary ganglion would not cause Horner's syndrome E. The pupil of the affected side is constricted. 12. Choose the best answer about primary visual cortex. A. Some cells in primary visual cortex respond best to non-moving stimuli. B. A reversing checkerboard, in which white squares turn black and vice versa, will activate every cell in primary visual cortex. C. Directionally-selective cells in the lateral geniculate are essential for directional selectivity of cortical cells. D. Color-selective cells in primary visual cortex are found only in layer 4. E. Both A and B are true 13. Choose the best answer concerning a newborn child with a drooping eyelid that completely covers the left eye. A. On the day of birth, cells in the left eye laminae of the lateral geniculate innervate only about 20% of the cells in layer 4 of the visual cortex. B. If the defect is corrected when the child is 2 weeks old, both eyes are likely to develop fairly normal vision. C. If the defect is never corrected, no axons from the lateral geniculate will be able to synapse in the visual cortex. D. If the defect is never corrected, the visual cortex on the right side of the brain will become smaller than the visual cortex on the left side of the brain. E. Both A and B are true. 14. Information from the lower nasal retina of the right eye would be found in all the following locations EXCEPT the: A. right optic tract B. right optic nerve C. left loop of Meyer D. left temporal lobe E. left lingual gyrus 15. Accommodation would be affected by damage to which of the following structures: A. left and right occipital cortex B. right cranial nerve III C. right Edinger Westfall nucleus D. A, B and C E. B and C 11

12 16. Which of the following statements is FALSE about the pathway that controls voluntary conjugate lateral gaze of the eyes: A. eye movement is triggered by activity in the frontal lobe B. internuclear ophthalmoplegia is caused by a lesion in this pathway C. stimulation of the frontal eye fields on one side causes deviation of the eyes to the opposite side D. a lesion of the MLF does not effect this movement E. the paramedian pontine reticular formation influences the nuclei of CN VI and III 17. Voluntary movement of your eyes to look from one stationary object to another in your visual field is known as: A. saccade B. smooth pursuit C. vergence D. nystagmus E. tracking movement 18. Choose the best answer concerning the retina. A. When light strikes a rod photoreceptor, rhodopsin binds to sodium channels in the outer segment membrane. B. Cone photoreceptors fire action potentials under conditions of bright light. C. Retinal ganglion cell axons comprise the optic nerve. D. The transmitter released at photoreceptor synapses is cgmp. E. Both A and B are true 19. Choose the best answer concerning the visual system. A. Visual cortex neurons predominately have center-surround receptive fields B. Some cells in layer 4 of striate cortex are directionally-selective. C. A lesion of parietal cortex will lead to selective loss of ability to recognize faces while leaving the ability to detect the motion of objects intact. D. Cells of one column in the striate cortex have the same orientation selectivity. E. Both A and B are true 20. Horner's syndrome would be caused by damage to which of the following structures: A. trigeminothalamic fibers B. ciliary ganglion C. cranial nerve III D. intermediolateral cell column E. optic radiations 21. Which of the following statements about the visual system is TRUE: A. the optic nerve is myelinated by schwann cells B. the sensitivity of the fovea is due to the convergence of cones C. an excess of aqueous humor results in papilledema D. the Loop of Meyer is located in the parietal lobe E. information from the upper retina terminates in the cuneus 12

13 22. Which of the following eye movements is used in the Accommodation reflex: A. saccade B. smooth pursuit C. nystagmus D. vergence E. tracking movement 23. Which of the following statements about the visual system is true? A. Rods hyperpolarize in response to light but depolarize in response to dark. B. Rods are found at all locations in the retina but cones are found only in the macula. C. Retinitis pigmentosa begins with degeneration of ganglion cells in the peripheral part of the retina. D. In the dark, sodium and potassium ions enter the rod outer segment through rhodopsin channels. 24. Choose the best answer regarding the visual system. A. Neurons in the lateral geniculate nucleus have receptive fields that respond to bars, edges, and direction of movement. B. Some cells in the visual cortex respond well to a vertical black line and a horizontal white line. C. Most visual centers in the temporal lobe contain neurons that are sensitive to moving stimuli. D. Visual areas in the parietal lobe are important for facial recognition E. None of the above are true. 1. D 9. D 17. A 2. D 10. B 18. C 3. A 11. C 19. D 4. D 12. A 20. D 5. E 13. B 21. E 6. D 14. A 22. D 7. C 15. D 23. A 8. A 16. D 24. E 13

14 The diagram on the left shows lesions in the visual pathways. For the indicated lesions, draw the VISUAL FIELD deficits for the left and right eyes in the places provided and then write the appropriate name (ophthalmic term) that describes the deficit. Left Right D E F 14

15 The diagram on the right shows VISUAL FIELD deficits for the left and right eyes. In the spaces provided in the left column: 1) indicate ONE place in the visual pathway where a lesion (damage) would produce that deficit. Be sure to indicate the side of the lesion; 2) write the name of the visual deficit using proper ophthalmic terminology. Location: Name: Location: Name: Location: Name: Location: Name: 15

16 The diagram on the right shows the VISUAL FIELDS for the left and right eyes. 1) Shade in the appropriate areas of the visual fields in the right column that correspond to a lesion in the location named in the left column. 2) In the space provided in the left column indicate the name of the visual deficit, including side of the lesion. 1. Location: RIGHT Optic Nerve 1 LEFT RIGHT Name: 2. Location: LEFT Lateral Geniculate Nucleus 2 Name: 3. Location: RIGHT Cuneus 3 Name: 4.Location: LEFT Optic Tract 4 Name: 16

17 VESTIBULAR AND AUDITORY SYSTEMS 1. Which of the following is part of the sensory apparatus involved in detection of static head position: A. cupula B. macula C. crista ampullaris D. otolithic membrane E. both B and D 2. Which of the following statements about the vestibular system is FALSE: A. the pathway for conscious perception of vestibular information involves VPL of thalamus B. some axons from the vestibular nuclei synapse on vestibular hair cells C. first-order vestibular neurons are pseudounipolar neurons D. some axons from the vestibular Nuclei travel in the juxtarestiform body E. some axons from the vestibular Ganglion travel in the juxtarestiform body 3. Choose the best answer concerning the vestibular system. A. Rotation of the head always leads to a decrease in the firing of some axons innervating the semicircular canals. B. Bending of a hair bundle in the direction of the kinocilium leads to depolarization of hair cell. C. The membrane properties of some hair cells in the utricle cause them to fire transiently, while others fire in a sustained manner. D. All hair cells in the left utricle are depolarized by tilting the head to the right. E. Both A and B are true. 4. Saccadic eye movements: A. are made voluntarily when deciding to change the point of visual fixation. B. can be controlled independently in each eye. C. are generally slow in velocity. D. are used to keep the image of a moving object on the fovea. E. are absent after spinal cord transection. 5. In the vestibulo-ocular reflex: A. the sensory input is from the hair cells of the basilar membrane. B. the amplitude of the response is regulated by activity from the macula. C. this reflex is mediated by the flocculus and nodulus. D. the pathway mediating this reflex involves the medial lemniscus. E. the sensory input is from the foveal region of the retina. 6. Which of the following statements about the vestibular and auditory systems is TRUE: A. the ampulla is part of the utricle that transduces information about static head position B. first-order neurons of both the vestibular and auditory system are bipolar neurons C. cell bodies of first-order vestibular neurons are found in the spiral ganglion D. information about head rotation is transduced by the macula E. the vestibular nuclei send axons to the cerebral cortex to evoke visceral responses like nausea 17

18 7. Which is TRUE about smooth pursuit eye movements: A. they are used to follow moving targets. B. they are a symptom of Huntington's disease. C. they are used to change fixation in a stationary environment. D. they are a symptom of Parkinson's disease. E. they can be made in the absence of a moving target. 8. Nystagmus A. may occur in response to moving visual stimuli. B. may occur in response to rotation of the patient. C. may be generated by irrigating one ear with warm water. D. may be a symptom of brain damage. E. all of the above statements are true. 9. Neurons in the vestibular ganglion synapse directly on all of the following EXCEPT: A. hair cells of the macula B. vestibular nuclei C. flocculus and nodulus D. hair cells of the semicircular canals E. ventral horn motoneurons 10. Choose the best answer concerning the vestibular system: A. One of the functions of perilymph is to help bend hair bundles of the semicircular canals during head rotation. B. When the head is tilted to the left, some eighth nerve axons in the utricle will fire more slowly than when the head is upright. C. Bending the hair bundle generates an action potential in the hair cell. D. First-order axons from the semicircular canals always fire action potentials while the head is rotating. E. Both A and B are true 11. Choose the best answer concerning the vestibular system: A. Ions such as potassium in the endolymph enter hair cells through mechanoreceptor-type channels in the stereocilia. B. The firing rate of CN VIII axons from the utricle signals both the direction and magnitude of tilt. C. Cells in the vestibular nuclei on the left side of the brainstem respond to head motion only to the left and not to the right. D. Adjacent stereocilia in a hair bundle move independently of one another. E. Both A and B are true. 12. Which of the following statements about the vestibular apparatus is FALSE: A. vestibular hair cells contain a kinocilium at their apical ends B. in the crista ampullares, stereocilia project into the otolithic membrane C. the membranous labyrinth is filled with endolymph D. the cupula is important in transduction of angular rotation of the head E. hair cells are innervated by bipolar neurons 18

19 13. In the vestibular system, which of the following is TRUE: A. information on head rotation is provided by the macula B. hair cell bundles in one cupula are oriented in random directions C. when the head is tilted, some hair cells in the utricle depolarize, some hyperpolarize, and some show no change D. all of the stereocilia on one vestibular hair cell are the same length E. during head rotation, the force exerted by the perilymph causes the cupula to bend 14. The direction and magnitude of head tilt is encoded by: A. the firing rate of vestibular hair cells B. the firing rate of CN VIII axons C. the degree of bending of the cupula D. the firing rate of the crista ampullares E. None of the above 15. Neurons in the vestibular nuclei synapse on all of the following EXCEPT: A. oculomotor neurons B. spinal motoneurons to neck muscles C. flocculus D. spinal motoneurons to axial body muscles E. cerebral cortex 16. Which of the following structures of the auditory system is NOT involved in amplifying sound to compensate for the loss of energy when sound travels from air to water: A. tympanic membrane B. external auditory meatus C. stapes footplate D. stapedius muscle E. actions of the malleus and incus 17. Which of the following statements about the cochlea is TRUE: A. there are 3 rows of inner hair cells and 1 row of outer hair cells B. outer hair cells are sensory in function but inner hair cells are motile C. 95% of afferent fibers in the cochlear division of cranial nerve VIII contact the inner hair cells D. 5% of efferent fibers in the cochlear division of cranial nerve VIII synapse on outer hair cells E. each inner hair cell is innervated by only one VIII nerve fiber 18. Deafness in one ear would result from destruction of which of the following structures on that side: A. cochlear nucleus B. superior olivary complex C. auditory cortex D. inferior colliculus E. medial geniculate nucleus 19

20 19. Axons from cell bodies in the medial geniculate nucleus travel in which of the following structures: A. lateral lemniscus B. brachium of inferior colliculus C. trapezoid body D. brachium of superior colliculus E. internal capsule 20. Choose the best answer about the auditory system: A. Hair cell axons synapse in the spiral ganglion. B. On each side of the head, the cochlea contains hair cells on two parallel membranes. C. The perilymph is a special fluid that bathes hair cell bodies in a high calcium concentration. D. The basilar membrane is displaced in response to sound. E. Both A and B are true. 21. Choose the best answer about the auditory system: A. Calcification of the ossicles in the left ear can impair the ability to tell where a sound is coming from. B. Very loud sounds that shear stereocilia off of hair cells can cause hearing loss. C. Loss of hair cells in the tympanic membrane is a common cause of impaired hearing. D. Motions of the stapes cause the tympanic membrane to move in and out. E. Both A and B are true. 22. Choose the best answer concerning the auditory system: A. The characteristic amplitude of a cell in the eighth nerve is the size of the action potentials that are fired in response to appropriate frequencies. B. In the cochlea, some hair cells respond transiently to a given tone while some others respond in a sustained manner. C. A sound of 250 Hz will excite some cells in the cochlear nucleus and will inhibit others. D. Cells in the auditory cortex on the right side of the brain respond better to sounds originating near the right ear than to sounds originating near the left ear. E. Both A and B are true. 23. Sensory information from the cochlea of both ears reaches all of the following nuclei EXCEPT: A. superior olivary nucleus B. dorsal cohlear nucleus C. inferior colliculus D. medial geniculate nucleus E. both ears are represented in all of these nuclei 20

21 24. Which statement about the auditory system is TRUE: A. loudness of sound is encoded by which eighth nerve axons fire B. hair cells in the basal region of the cochlea respond best to high frequencies C. the basilar membrane separates the scala tympani from the scala vestibuli D. outer hair cells transduce sound information and transmit it to the CNS E. spiral ganglion neurons are pseudounipolar in morphology 25. Concerning the processing of sound by the auditory system: A. bending of stereocilia produces action potentials in hair cells B. in the brainstem, convergence of excitatory interneurons allow cells to respond to narrower ranges of frequencies C. inhibitory interneurons in the spiral ganglion produce the characteristic frequency to which each eighth nerve axon responds D. the location of a sound source is determined by the timing and intensity of sound information E. louder sounds decrease the firing rate of eighth nerve axons compared to softer sounds 1. E 9. E 17. C 25. D 2. C 10. B 18. A 3. E 11. E 19. E 4. A 12. B 20. D 5. C 13. C 21. E 6. B 14. B 22. C 7. A 15. E 23. B 8. E 16. D 24. B 21