51-100

Question 1

51. Conduction velocity of afferent fibers is >I20 mls.

For questions 43 to 52, match the description with the structure.
A. Golgi’s tendon organ
B. muscle spindle
C. both
D. neither

Answer 1

D. neither

Question 2

52. contains dynamic nuclear bag, static nuclear bag, and nuclear chain fibers

For questions 43 to 52, match the description with the structure.
A. Golgi’s tendon organ
B. muscle spindle
C. both
D. neither

Answer 2

B

Question 3

53. Each of the following is true of decerebrate rigidity except
    A. It results from tonic activity in the vestibulospinal and pontine
    reticulospinal neurons.
    B. It is reduced by cutting dorsal roots.
    C. It is reduced by destruction of the anterior lobe of the cerebellum.
    D. It occurs with transection between the colliculi.
    E. There is increased gamma motor neuron activity.

Answer 3

C

K&S pp. 654, 817, 821. Destruction of the anterior lobe of the cerebellum
releases the cells of origin of the lateral vestibular tract from inhibition by
Purkinje’s cells, thereby facilitating extensor motor neurons.

Question 4

54. an antidromic wave in motor fibers traveling to anterior horn cells

For questions 54 to 59, match the reflex or response with the description. Each
answer may be used once, more than once, or not at all.
A. clasp-knife response
B. flexion reflex
C. F response
D. H response
E. M response
F. stretch reflex

Answer 4

C

For questions 54-59 see V&A pp. 56-58; K&S pp. 716-717,730.

Question 5

55. has phasic and tonic components

For questions 54 to 59, match the reflex or response with the description. Each
answer may be used once, more than once, or not at all.
A. clasp-knife response
B. flexion reflex
C. F response
D. H response
E. M response
F. stretch reflex

Answer 5

F

Question 6

56. a protective reflex involving polysynaptic reflex pathways

For questions 54 to 59, match the reflex or response with the description. Each
answer may be used once, more than once, or not at all.
A. clasp-knife response
B. flexion reflex
C. F response
D. H response
E. M response
F. stretch reflex

Answer 6

B

Question 7

57. the electrical equivalent of the tendon reflex

For questions 54 to 59, match the reflex or response with the description. Each
answer may be used once, more than once, or not at all.
A. clasp-knife response
B. flexion reflex
C. F response
D. H response
E. M response
F. stretch reflex

Answer 7

D

Question 8

58. the direct motor response obtained by stimulating a mixed motor-sensory nerve

For questions 54 to 59, match the reflex or response with the description. Each
answer may be used once, more than once, or not at all.
A. clasp-knife response
B. flexion reflex
C. F response
D. H response
E. M response
F. stretch reflex

Answer 8

E

Question 9

59. A length-dependent change in muscle force when the limb is passively moved

For questions 54 to 59, match the reflex or response with the description. Each
answer may be used once, more than once, or not at all.
A. clasp-knife response
B. flexion reflex
C. F response
D. H response
E. M response
F. stretch reflex

Answer 9

A

Question 10

60. Contraction of the detrusor muscle of the bladder is achieved through activation of
    A. parasympathetic fibers from T9 to L1
    B. parasympathetic fibers from S2 to S4
    C. sympathetic fibers from T9 to L1
    D. sympathetic fibers from S2 to S4
    E. pudendal nerves

Answer 10

B.

K&S p. 968-969

Question 11

61. Which is true of events occurring after a typical axon is severed?
    A. Chromatolysis is always associated with decreased protein synthesis.
    B. Retraction bulbs form only at the proximal end of the cut nerve.
    C. Terminal degeneration leads to the loss of presynaptic terminals.
    D. Wallerian degeneration occurs before terminal degeneration.
    E. Wallerian degeneration leads to loss of the proximal axon segment

Answer 11

C

K&S p. 1108. Chromatolysis is associated with increased protein synthesis.
Retraction bulbs, from the buildup of transported materials, occur at both the
proximal and the distal ends of the cut nerve. Wallerian degeneration begins
in the distal end of the axon about 1 week after initial degenerative changes
begin in the axon terminal.

Question 12

62. Agents that increase the formation of cerebrospinal fluid (CSF) include
    I. carbon dioxide
    II. norepinephrine
    III. volatile anesthetic agents
    IV. carbonic anhydrase inhibitors
    A. I, II, III
    B. I, III
    C. II, IV
    D. IV
    E. all of the above

Answer 12

B. I. carbon dioxide, III. volatile anesthetic agents

Carp p. 14. Carbon dioxide and volatile anesthetic agents increase cerebrospinal
fluid (CSF) production, whereas carbonic anhydrase inhibitors and norepinephrine
inhibit CSF production.

Question 13

63. The main neurotransmitter of the Renshaw cell is thought to be
    A. acetylcholine
    B. GABA
    C. glutamate
    D. glycine
    E. histamine

Answer 13

D. glycine

K&S p. 78

Question 14

64. auditory nerve

For questions 64 to 68, match the wave in the brainstem auditory evoked response
with the structure with which it is most closely associated. Each response may be
used once, more than once, or not at all.
A. wave I
B. wave II
C. wave III
D. wave IV
E. wave V

Answer 14

A. wave I

For questions 64-68 see V&A pp. 36-37.

Question 15

65. cochlear nuclei

For questions 64 to 68, match the wave in the brainstem auditory evoked response
with the structure with which it is most closely associated. Each response may be
used once, more than once, or not at all.
A. wave I
B. wave II
C. wave III
D. wave IV
E. wave V

Answer 15

B

Question 16

66. inferior colliculus
    For questions 64 to 68, match the wave in the brainstem auditory evoked response
    with the structure with which it is most closely associated. Each response may be
    used once, more than once, or not at all.
    A. wave I
    B. wave II
    C. wave III
    D. wave IV
    E. wave V

Answer 16

E. wave V

Question 17

67. lateral lemniscus

For questions 64 to 68, match the wave in the brainstem auditory evoked response
with the structure with which it is most closely associated. Each response may be
used once, more than once, or not at all.
A. wave I
B. wave II
C. wave III
D. wave IV
E. wave V

Answer 17

D.wave IV

Question 18

68. superior olivary nucleus

For questions 64 to 68, match the wave in the brainstem auditory evoked response
with the structure with which it is most closely associated. Each response may be
used once, more than once, or not at all.
A. wave I
B. wave II
C. wave III
D. wave IV
E. wave V

Answer 18

C

Question 19

69. Absence or delay implies cervical cord disease.

For questions 69 to 72, match the wave in the somatosensory evoked potential with
the description. Each response may be used once, more than once, or not at all.
A. Erb’s point
B. N11
C. N13/P13
D. N19
E. P22

Answer 19

B. N11

For questions 69-72 see V&A pp. 38-39.

Question 20

70. Absence or delay implies peripheral nerve disease.

For questions 69 to 72, match the wave in the somatosensory evoked potential with
the description. Each response may be used once, more than once, or not at all.
A. Erb’s point
B. N11
C. N13/P13
D. N19
E. P22

Answer 20

A

Question 21

71. Absence or delay implies a lesion in the lower medulla.

For questions 69 to 72, match the wave in the somatosensory evoked potential with
the description. Each response may be used once, more than once, or not at all.
A. Erb’s point
B. N11
C. N13/P13
D. N19
E. P22

Answer 21

C. N13/P13

Question 22

72. is found at the shoulder

For questions 69 to 72, match the wave in the somatosensory evoked potential with
the description. Each response may be used once, more than once, or not at all.
A. Erb’s point
B. N11
C. N13/P13
D. N19
E. P22

Answer 22

A. Erb’s point

Question 23

73. critical threshold below which functional impairment occurs

For questions 73 to 75, match the rate of cerebral blood flow with the description.
Each response may be used once, more than once, or not at all.
A. 75 mL/100 glmin
B. 55 mL/100 glmin
C. 23 mL/100 glmin
D. 17 mL/100 glmin
E. 8 mL/100 g/min

Answer 23

C.

For questions 73-75 see V&A p. 828. The state of hypoperfusion between

Question 24

74. Irreversible infarction occurs below this flow rate.

For questions 73 to 75, match the rate of cerebral blood flow with the description.
Each response may be used once, more than once, or not at all.
A. 75 mL/100 glmin
B. 55 mL/100 glmin
C. 23 mL/100 glmin
D. 17 mL/100 glmin
E. 8 mL/100 g/min

Answer 24

E. 8 mL/100 g/min

a cerebral blood flow of 8 and 23 mL/100 g/min is known as the ischemic

Question 25

75. normal cerebral blood flow For questions 73 to 75, match the rate of cerebral blood flow with the description. Each response may be used once, more than once, or not at all. A. 75 mL/100 glmin B. 55 mL/100 glmin C. 23 mL/100 glmin D. 17 mL/100 glmin E. 8 mL/100 g/min

Answer 25

B penumbra. The biochemical abnormalities, including depletion of ATP and creatine phosphate and increase of K+ level (from injured cells), can be reversed if adequate blood flow is restored in a timely fashion.

Question 26

76. Axons of these cells mainly comprise the molecular layer. For questions 76 to 83, match the cerebellar cortical cell with the description. Each response may be used once, more than once, or not at all. A. basket cells B. Golgi's cells C. granule cells D. Purkinje's cells E. stellate cells

Answer 26

C For questions 76-83 see K&S pp. 835-840. The cerebellar cortex consists of three layers that contain five cell types. The molecular layer (outermost) is composed of the axons of the granule cells (parallel fibers), stellate and basket cells (interneurons), and dendrites of the underlying Purkinje's cells. The Purkinje's cell layer (middle) contains the cell bodies of the Purkinje's neurons. They are the sole output of the cerebellar cortex and are inhibitory. The granular (innermost) layer contains numerous granule cells (excitatory; utilize glutamate), a few Golgi's cells, and glomeruli (where cells in the granular layer form complex synaptic contacts with the incoming mossy fibers). Afferents to the cortex terminate either in the granule cell layer as mossy fibers or on the dendrites of Purkinje's cells as climbing fibers. Both mossy and climbing fiber inputs are excitatory to both the deep cerebellar nuclei and the cortex. Stellate and basket cells directly inhibit Purkinje's and Golgi's cells, and Golgi's cells inhibit granule cells.

Question 27

77. reside in the granular layer together with granule cells For questions 76 to 83, match the cerebellar cortical cell with the description. Each response may be used once, more than once, or not at all. A. basket cells B. Golgi's cells C. granule cells D. Purkinje's cells E. stellate cells

Answer 27

B

Question 28

78. excitatory For questions 76 to 83, match the cerebellar cortical cell with the description. Each response may be used once, more than once, or not at all. A. basket cells B. Golgi's cells C. granule cells D. Purkinje's cells E. stellate cells

Answer 28

C

Question 29

79. Mossy fibers synapse here. For questions 76 to 83, match the cerebellar cortical cell with the description. Each response may be used once, more than once, or not at all. A. basket cells B. Golgi's cells C. granule cells D. Purkinje's cells E. stellate cells

Answer 29

C. granule cells

Question 30

80. Climbing fibers synapse here. For questions 76 to 83, match the cerebellar cortical cell with the description. Each response may be used once, more than once, or not at all. A. basket cells B. Golgi's cells C. granule cells D. Purkinje's cells E. stellate cells

Answer 30

D

Question 31

81. the only cerebellar cortical output For questions 76 to 83, match the cerebellar cortical cell with the description. Each response may be used once, more than once, or not at all. A. basket cells B. Golgi's cells C. granule cells D. Purkinje's cells E. stellate cells

Answer 31

D

Question 32

82. directly inhibit Purkinje's cells together with stellate cells For questions 76 to 83, match the cerebellar cortical cell with the description. Each response may be used once, more than once, or not at all. A. basket cells B. Golgi's cells C. granule cells D. Purkinje's cells E. stellate cell

Answer 32

A

Question 33

83. utilize glutamate For questions 76 to 83, match the cerebellar cortical cell with the description. Each response may be used once, more than once, or not at all. A. basket cells B. Golgi's cells C. granule cells D. Purkinje's cells E. stellate cells

Answer 33

C

Question 34

84. Which is true of the macule of the utricle and saccule when the head is held erect? A. The utricular macule is oriented horizontally, and the saccular macule is oriented vertically. B. The utricular macule is oriented vertically, and the saccular macule is oriented horizontally. C. They are both oriented horizontally. D. They are both oriented vertically. E. None of the above is true.

Answer 34

A. The utricular macule is oriented horizontally, and the saccular macule is oriented vertically. K&S pp. 804-805

Question 35

85. The sensation of sharp, pricking pain is mediated by A. A-alpa fibers B. A-beta fibers C. A-delta fibers D. A-gamafibers E. C fibers

Answer 35

D K&S p. 432

Question 36

86. Which is true of synaptic transmission in automatic ganglia? A. Neuronal ACh receptors contain four types of subunits. B. The slow excitatory postsynaptic potential (EPSP) is produced by muscarinic receptors closing Na+ and Ca2+ channels while opening K+ channels. C. The slow inhibitory postsynaptic potential (IPSP) is mediated by activation of muscarinic receptors that close K+ channels. D. The fast EPSP is mediated by nicotinic ACh receptors. E. Peptides are never co-released with ACh.

Answer 36

D. The fast EPSP is mediated by nicotinic ACh receptors. For questions 84-86 see K&S pp. 969-970. Unlike the ACh receptors at the neuromuscular junction, the ACh receptors in autonomic ganglia contain only two types of subunits. The fast excitatory postsynaptic potential (EPSP) is mediated by nicotinic ACh receptors, the slow EPSP is mediated by muscarinic receptors opening Na+ and Ca2+ channels and closing K+ channels, and the slow inhibitory postsynaptic potential (IPSP) is mediated by muscarinic receptors that open K+ channels. A variety of peptides that appear to be modulatory in action may be co-released with ACh.

Question 37

87. Each of the following is true of the neural innervation of the bladder except A. Increased postganglionic sympathetic activity results in bladder wall contraction. B. Increased postganglionic sympathetic activity results in a-adrenergic inhibition of parasympathetics in the pelvic ganglion. C. Motor neurons in the ventral horn of the sacral spinal cord innervate the external sphincter. D. Parasympathetic activity promotes bladder emptying. E. The internal sphincter is innervated by sympathetic fibers

Answer 37

A. Increased postganglionic sympathetic activity results in bladder wall contraction. K&S pp. 968-969. Increased sympathetic activity results in bladder wall relaxation.

Question 38

88. Fibers from the superior salivatory nucleus synapse in the I. pterygopalatine ganglion II. geniculate ganglion III. submandibular ganglion IV. trigeminal ganglion A. I, II, III B.I, III C II, IV D. IV E. all of the above

Answer 38

B. I. pterygopalatine ganglion, III. submandibular ganglion Carp pp. 171-172.

Question 39

89. Ipsilateral corticocortical association fibers arise from cells in cortical layers A. I and II B. II and Ill C Ill and IV D. IV and V E. V and Vl

Answer 39

B. II and Ill Carp p. 393.

Question 40

90. As the membrane of a motor neuron becomes increasingly depolarized. A. Both EPSP and IPSP decrease. B. Both EPSP and IPSP increase. C EPSP decreases. and IPSP increases. D. EPSP increases, and IPSP decreases. E. There is no change in IPSP, but EPSP increases

Answer 40

C K&S p. 210.K&S p. 210.

Question 41

91. Each of the following is true of Renshaw cells except that A. They are part of a negative feedback loop to the motor neurons. B. They facilitate la inhibitory interneurons that act on antagonist motor neurons. C They inhibit motor neurons that innnervate synergist muscles. D. They make divergent connections to motor neurons. E. They receive input from descending pathways.

Answer 41

B. They facilitate la inhibitory interneurons that act on antagonist motor neurons. K&S pp. 78,720-721. Renshaw cells inhibit la inhibitory interneurons that act on antagonist motor neurons.

Question 42

92. involved in the control of posture For questions 92 to 96, match the nucleus with the description. Each response may be used once, more than once, or not at all. A. inferior vestibular nucleus B. lateral vestibular nucleus C. medial vestibular nucleus D. superior vestibular nucleus E. none of the above

Answer 42

B. lateral vestibular nucleus For questions 92-96 see K&S pp. 810-841. Part of the lateral vestibulospinal nucleus (Deiters' nucleus) receives direct inhibitory input from Purkinje's cells in the cerebellar vermis. Decerebrate rigidity is exacerbated if the portion of the cerebellum connected to Deiters' nucleus is interrupted because of removal of this inhibitory action. The lateral vestibulospinal tract has a facilitatory effect on both alpha and gamma neurons that innervate muscles in the limbs; this tonic excitation of the extensors of the leg and the flexors of the arm helps in the maintenance of posture.

Question 43

93. This nucleus and the medial vestibular nucleus are involved in mediating vestibulo-ocular reflexes. For questions 92 to 96, match the nucleus with the description. Each response may be used once, more than once, or not at all. A. inferior vestibular nucleus B. lateral vestibular nucleus C. medial vestibular nucleus D. superior vestibular nucleus E. none of the above

Answer 43

D

Question 44

94. also known as Deiters' nucleus For questions 92 to 96, match the nucleus with the description. Each response may be used once, more than once, or not at all. A. inferior vestibular nucleus B. lateral vestibular nucleus C. medial vestibular nucleus D. superior vestibular nucleus E. none of the above

Answer 44

B

Question 45

95. integrates input from the vestibular labyrinth and the cerebellum For questions 92 to 96, match the nucleus with the description. Each response may be used once, more than once, or not at all. A. inferior vestibular nucleus B. lateral vestibular nucleus C. medial vestibular nucleus D. superior vestibular nucleus E. none of the above

Answer 45

A

Question 46

96. Decerebrate rigidity is due to the unopposed excitatory effect of the reticulospinal tract and the tract originating from this nucleus. For questions 92 to 96, match the nucleus with the description. Each response may be used once, more than once, or not at all. A. inferior vestibular nucleus B. lateral vestibular nucleus C. medial vestibular nucleus D. superior vestibular nucleus E. none of the above

Answer 46

B. lateral vestibular nucleus

Question 47

97. Which of the following modifications of proteins does not occur in the Golgi's complex? A. attachment of fatty acids B. formation of 0-linked sugars C. initiation of N-linked glycosylation D. sugar phosphorylation E. sulfation of tyrosine residues

Answer 47

C Hall pp. 10,135. The initial steps of N-linked glycosylation take place in the endoplasmic reticulum.

Question 48

98. alpa-bungarotoxin For questions 98 to 104, match the toxin with the description. Each response may be used once, more than once, or not at all. A. binds to the ACh receptor B. blocks reuptake of dopamine C. blocks voltage-gated K+ channels D. blocks voltage-gated Na+ channels E. depletes norepinephrine (NE) from vesicles F. inhibits GTP hydrolysis G. prevents presynaptic release of quanta of ACh

Answer 48

A. binds to the ACh receptor For questions 98-104 see Hall p. 200; K&S pp. 114,153,270,286,307-308.

Question 49

99. botulinum For questions 98 to 104, match the toxin with the description. Each response may be used once, more than once, or not at all. A. binds to the ACh receptor B. blocks reuptake of dopamine C. blocks voltage-gated K+ channels D. blocks voltage-gated Na+ channels E. depletes norepinephrine (NE) from vesicles F. inhibits GTP hydrolysis G. prevents presynaptic release of quanta of ACh

Answer 49

G

Question 50

100. cholera For questions 98 to 104, match the toxin with the description. Each response may be used once, more than once, or not at all. A. binds to the ACh receptor B. blocks reuptake of dopamine C. blocks voltage-gated K+ channels D. blocks voltage-gated Na+ channels E. depletes norepinephrine (NE) from vesicles F. inhibits GTP hydrolysis G. prevents presynaptic release of quanta of ACh

Answer 50

F