Chapter 4 Neurobiology For questions 1 to 5, match the substances with the description. A. bone growth factors B. recombinant human bone morphogenic proteins C. both D. neither 1. a strong mitogen 2. a potent inducer of bone cell differentiation 3. act on differentiated mesenchymal cells of the chondro-osseous lineage 4. act on undifferentiated mesenchymal cells 5. polypeptides 6. Which of the following is the correct representation of the subunits of the acetylcholine (ACh) receptor at the neuromuscular junction? A. αβγδ B. α2βγδ C. αβ2γδ D. αβγ2δ E. αβγδ2 7. Which of the following is true of the α subunit of the nicotinic acetylcholine receptor? A. It contains four hydrophobic transmembrane portions. B. The binding site is not located on the α subunit. C. The cytoplasmic loop is the most highly conserved portion of the subunit. D. The N-terminal is extracellular, and the C-terminal is intracellular. E. The transmembrane portion is the least conserved segment. 8. The number of binding sites on the nicotinic acetylcholine receptor is A. 1 B. 2 C. 3 D. 4 E. 5 For questions 9 and 10, match the description with the receptor. A. α subunit of GABAA receptor B. β subunit of GABAA receptor C. both D. neither 9. binds γ-aminobutyric acid (GABA) 10. binds benzodiazepines For questions 11 to 16, match the receptor with the description. Each response may be used once, more than once, or not at all. A. GABA receptor B. glutamate receptor C. glycine receptor D. nicotinic ACh receptor E. serotonin (5-HT) receptor 11. most closely linked with synaptic plasticity and cell death 12. GABA and this receptor are permeable to chloride ions. 13. binds strychnine 14. binds benzodiazepine 15. One type of this receptor is both ligand and voltage regulated. 16. One type of this receptor is blocked by magnesium ions. For questions 17 to 21, match the description with the receptor. A. kainate receptor only B. N-methyl-D-aspartate (NMDA) receptor only C. quisqualate/alpha-amino-3-hydroxy-5-methyl-4-isoxazoleproprionic acid (AMPA) receptor only D. A and B E. A, B, and C 17. significantly permeable to calcium ions 18. permeable to monovalent cations 19. ligand-gated 20. voltage-gated 21. blocked by magnesium ions 22. Which of the following is true of acetylcholine (ACh) release from the neuromuscular junction? A. One molecule of ACh equals 10,000 quanta. B. One quanta contains 10,000 molecules of ACh. C. One quanta equals 1 molecule of ACh. D. One vesicle contains 10,000 quanta. E. One vesicle contains 10 molecules. 23. Pro-opiomelanocortin is a precursor of I. adrenocorticotropic hormone (ACTH) II. α-melanocyte-stimulating hormone (MSH) III. β-endorphin IV. β-lipotropin A. I, II, III B. I, III C. II, IV D. IV E. all of the above 24. Removal of calcium ions from the cytosol in a presynaptic nerve terminal following an action potential is thought to occur by I. active transport II. binding to cytosolic proteins III. transport into intracellular calcium-storage vesicles IV. reversal of flow through voltage-gated calcium channels A. I, II, III B. I, III C. II, IV D. IV E. all of the above 25. Each of the following occurs in phototransduction except A. Activated rhodopsin activates a G protein. B. Activation of cyclic guanosine monophosphate (cGMP) phosphodiesterase increases hydrolysis of cGMP to 5′-GMP. C. Current through a cGMP-activated sodium channel decreases. D. Rhodopsin is activated when light converts bound 11-cis retinal to all-trans retinal. E. The decreased concentration of cGMP results in depolarization of the plasma membrane. 26. Each of the following is true of G proteins except A. Each G protein is regulated by only one type of receptor. B. Each G protein may regulate multiple effectors. C. The α subunit binds guanosine triphosphate (GTP). D. The β and γ subunits help anchor the α subunit to the plasma membrane. E. The β and γ subunits modulate guanosine diphosphate (GDP)/GTP exchange. For questions 27 to 33, match the second messenger with the description. Each response may be used once, more than once, or not at all. A. calcium B. 1, 2-diacylglycerol (DAG) C. cyclic adenosine monophosphate (cAMP) D. cGMP E. IP3 27. D1 receptors act by this second messenger. 28. increased by nitric oxide 29. hydrolyzed by phospholipase C 30. synergistically activates protein kinase C with calcium 31. binds to calmodulin 32. Photoreception utilizes this second messenger. 33. opens a calcium channel in the endoplasmic reticulum, releasing free calcium into the cytosol 34. Each of the following is true of the Na+/K+ pump except that it A. contributes to the resting potential of the cell B. hyperpolarizes the membrane C. is electrogenic D. transports 3 Na+ ions out for 2 K+ ions in E. utilizes 2 molecules of adenosine triphosphate (ATP) for every 3 Na+ ions transported 35. Each of the following is true of events occurring during the action potential except A. sudden increase in conductance of Na results in depolarization. B. Chloride permeability increases during depolarization. C. During hyperpolarization, the conductance of Na is lower than normal, and the conductance of K is higher than normal. D. The decrease in Na permeability, occurring as the action potential reaches a peak, results from inactivation of Na channels. E. The presence of voltage-dependent K channels is to allow faster repolarization. 36. The velocity of an action potential increases with a A. high transmembrane resistance, low internal resistance, and high membrane capacitance B. high transmembrane resistance, low internal resistance, and low membrane capacitance C. low transmembrane resistance, high internal resistance, and high membrane capacitance D. low transmembrane resistance, low internal resistance, and high membrane capacitance E. low transmembrane resistance, low internal resistance, and low membrane capacitance 37. Which of the following is true of myelination? A. It has no effect on transmembrane resistance but increases membrane capacitance. B. It decreases both transmembrane resistance and membrane capacitance. C. It decreases transmembrane resistance and increases membrane capacitance. D. It increases transmembrane resistance and decreases membrane capacitance. E. It increases both transmembrane resistance and membrane capacitance. For questions 38 to 40, match the description with the potential. A. end-plate potential B. miniature end-plate potential C. both D. neither 38. usually depolarizes muscle cells past threshold 39. occurs in unstimulated cells 40. produces a miniature action potential 41. Inhibitory postsynaptic potentials are produced when a transmitter opens channels permeable to A. Cl− only B. Cl− or K+ C. Na+only D. Na+ or Cl− E. Na+ or K+ 42. Which of the following is true of axonal transport? A. Dynamin does not use ATP. B. Dynein is the motor for anterograde fast axonal transport. C. Fast axonal transport occurs primarily along neurofilaments. D. Kinesin is the motor for retrograde fast axonal transport. E. Slow axonal transport occurs at 200 to 400 mm/day. For questions 43 to 52, match the description with the structure. A. Golgi’s tendon organ B. muscle spindle C. both D. neither 43. Discharge increases with passive stretch. 44. Discharge increases with active contraction. 45. in series with extrafusal fibers 46. in parallel with extrafusal fibers 47. sensitive to muscle tension 48. sensitive to muscle length and velocity of length change 49. innervated by group I (large myelinated) fibers 50. innervated by group II (small myelinated) fibers 51. Conduction velocity of afferent fibers is >120 m/s. 52. contains dynamic nuclear bag, static nuclear bag, and nuclear chain fibers 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. 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 54. an antidromic wave in motor fibers traveling to anterior horn cells 55. has phasic and tonic components 56. aprotective reflex involving polysynaptic reflex pathways 57. the electrical equivalent of the tendon reflex 58. the direct motor response obtained by stimulating a mixed motor-sensory nerve 59. A length-dependent change in muscle force when the limb is passively moved 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 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. 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 63. The main neurotransmitter of the Renshaw cell is thought to be A. acetylcholine B. GABA C. glutamate D. glycine E. histamine 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 64. auditory nerve 65. cochlear nuclei 66. inferior colliculus 67. lateral lemniscus 68. superior olivary nucleus 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 69. Absence or delay implies cervical cord disease. 70. Absence or delay implies peripheral nerve disease. 71. Absence or delay implies a lesion in the lower medulla. 72. is found at the shoulder 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 g/min B. 55 mL/100 g/min C. 23 mL/100 g/min D. 17 mL/100 g/min E. 8 mL/100 g/min 73. critical threshold below which functional impairment occurs 74. Irreversible infarction occurs below this flow rate. 75. normal cerebral blood flow 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 76. Axons of these cells mainly comprise the molecular layer. 77. reside in the granular layer together with granule cells 78. excitatory 79. Mossy fibers synapse here. 80. Climbing fibers synapse here. 81. the only cerebellar cortical output 82. directly inhibit Purkinje’s cells together with stellate cells 83. utilize glutamate 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. 85. The sensation of sharp, pricking pain is mediated by A. Aα fibers B. Aβ fibers C. Aγ fibers D. Aδ fibers E. C fibers 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. 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 α-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. 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 89. Ipsilateral corticocortical association fibers arise from cells in cortical layers A. I and II B. II and III C. III and IV D. IV and V E. V and VI 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. 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 Ia 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. 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 92. involved in the control of posture 93. This nucleus and the medial vestibular nucleus are involved in mediating vestibulo-ocular reflexes. 94. also known as Deiters’ nucleus 95. integrates input from the vestibular labyrinth and the cerebellum 96. Decerebrate rigidity is due to the unopposed excitatory effect of the reticulospinal tract and the tract originating from this nucleus. 97. Which of the following modifications of proteins does not occur in the Golgi’s complex? A. attachment of fatty acids B. formation of O-linked sugars C. initiation of N-linked glycosylation D. sugar phosphorylation E. sulfation of tyrosine residues 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 98. α-bungarotoxin 99. botulinum 100. cholera 101. cocaine 102. reserpine 103. tetraethylammonium (TEA) 104. tetrodotoxin 105. At the equilibrium potential of potassium, A. The electrical force equals the chemical force. B. The net electrical force is zero. C. The net chemical force is zero. D. There is no movement of K+ ions across the membrane. E. none of the above 106. Each of the following is true of G protein activation and deactivation except A. Activation of any G protein will inhibit the activation of other G proteins in the membrane. B. Hydrolysis of bound GTP to GDP inactivates a G protein. C. The βγ subunit stabilizes the binding of GDP. D. The βγ subunit stabilizes the binding of GTP. E. When activated, the α subunit’s affinity for the βγ subunit decreases. 107. The effect of succinylcholine at the neuromuscular junction is A. amplified by increased muscle temperature B. hyperpolarization C. not reversed by anticholinesterase agents D. not similar to that of decamethonium E. similar to that of D-tubocurarine For questions 108 to 111, match the area in the somatic sensory cortex with the receptors. Each response may be used once, more than once, or not at all. A. area 1 B. area 2 C. area 3a D. area 3b 108. muscle stretch receptors in deep tissue 109. pressure and joint position in deep tissue 110. slowly and rapidly adapting receptors in the skin 111. rapidly adapting receptors in the skin 112. Each of the following is true of the dorsal-column medial lemniscal system except A. Proprioception from the leg is relayed in the dorsal columns. B. Second-order neurons cross the midline in the medial lemniscus C. Thalamic neurons project to the primary somatic sensory cortex (SI). D. Thalamic neurons project to the secondary somatic sensory cortex (SII). E. Touch and vibration sense from the arm is relayed in the dorsal columns. For questions 113 to 121, match the region of the cerebellum with the clinical sign or symptom. Each response may be used once, more than once, or not at all. A. cerebellar hemisphere, intermediate part (interposed nuclei) B. cerebellar hemisphere, lateral part (dentate nuclei) C. flocculonodular (lateral vestibular nucleus) D. vermis (fastigial nucleus) E. none of the above 113. truncal ataxia 114. appendicular ataxia 115. terminal tremor 116. nystagmus 117. scanning speech 118. hypertonia 119. Hypotonia is seen in lesions of the interposed nuclei or of this portion. 120. decomposition of multijoint movements 121. delay in initiating movements 122. In the formation of nitric oxide, nitric oxide synthetase acts on the substrate A. arginine B. citrulline C. lysine D. ornithine E. tyrosine 123. The pineal gland synthesizes melatonin from A. acetylcholine B. dopamine C. histidine D. norepinephrine E. serotonin For questions 124 to 128, match the receptor with the description. Each response may be used once, more than once, or not at all. A. muscarinic receptor B. nicotinic receptor C. both D. neither 124. binds ACh 125. found in skeletal muscle 126. found in sympathetic neurons 127. blocked by hexamethonium 128. activates a second messenger system that closes a K+ channel 129. The EPSP in spinal motor neurons results from the opening of A. Cl− channels only B. Cl− and Na+ channels C. K+ channels only D. Na+ and K+ channels E. Na+ and Cl− channels 130. The response of the carotid sinus to an increase in blood pressure is a I. decrease in peripheral resistence II. decrease in heart rate III. decrease in force of contraction IV. decrease in blood pressure A. I, II, III B. I, III C. II, IV D. IV E. all of the above For questions 131 to 137, match the description with the structure. A. thick filaments B. thin filaments C. both D. neither 131. contains actin 132. contains myosin 133. contains tropomysin 134. contains troponin 135. binds ADP during rest 136. Sarcomeres contain them. 137. attached to the Z disks 138. Which of the following is true of skeletal muscle contraction? A. Calcium binds to tropomysin. B. Rotation of myosin heads pulls thin filaments toward the center of the sarcomere. C. The detachment of cross bridges does not require ATP. D. The dissociation of actin from myosin uses energy from the hydrolysis of GTP. E. When muscle relaxes, calcium diffuses into the sarcoplasmic reticulum from the intracellular space. 139. The resting potential of a neuron is approximately A. −90 mV B. −65 mV C. −50 mV D. +50 mV E. +65 mV 140. Each of the following agents promote alcohol dehydrogenase (ADH) release except A. alcohol B. angiotensin II C. decreased blood volume D. vomiting E. warmth of skin 141. Each of the following is a criterion that a chemical messenger should fulfill to be considered a transmitter except A. A specific mechanism exists for removing it from its site of action. B. It is present in the presynaptic terminal and is released in amounts sufficient to exert its action on the postsynaptic neuron or effector organ. C. It is synthesized in the neuron. D. The enzymes that catalyzes the steps in its synthesis are cytoplasmic. E. The exogenously applied substance should mimic the action of the endogenously released transmitter. 142. Each of the following is considered a neurotransmitter except A. epinephrine B. glycine C. histamine D. serotonin E. vasoactive intestinal polypeptide (VIP) 143. Each of the following organs is innervated by both the sympathetic and parasympathetic systems except the A. gastrointestinal tract B. heart C. lungs and bronchi D. salivary glands E. sweat glands 144. Each of the following is true of gamma motor neurons except A. Their activation during active muscle contraction allows muscle spindles to sense changes in length. B. Their activity is increased after lesions of the spinocerebellum. C. They innervate intrafusal fibers. D. Dynamic gamma motor neurons innervate dynamic nuclear bag fibers only. E. Static gamma motor neurons innervate nuclear chain fibers and static nuclear bag fibers. 145. Neurotransmitters that are found in major descending pain pathways from the pons and medulla are I. dopamine II. norepinephrine III. acetylcholine IV. serotonin A. I, II, III B. I, III C. II, IV D. IV E. all of the above 146. Cell groups that have concentric receptive fields include I. retinal ganglion cells II. simple cells of the primary visual cortex III. lateral geniculate cells IV. complex cells of the primary visual cortex A. I, II, III B. I, III C. II, IV D. IV E. all of the above For questions 147 to 151, match the sensory receptor with the description. Each response may be used once, more than once, or not at all. A. free nerve endings B. Meissner’s corpuscles C. Merkel’s receptors D. pacinian corpuscles E. Ruffini’s corpuscles 147. a subcutaneous, slowly adapting receptor 148. a rapidly adapting receptor found in the dermal papillae 149. a receptor subserving pressure and with a small receptive field 150. a rapidly adapting receptor more sensitive to high-frequency stimulation than low-frequency stimulation 151. a nociceptor
< div class='tao-gold-member'>
Related posts:
