NBR 2 - Neurobiology Flashcards
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
Jawab : A
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
2. a potent inducer of bone cell differentiation
Jawab : B
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
3. act on differentiated mesenchymal cells of the chondro-osseous lineage
Jawab : A
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
4. act on undifferentiated mesenchymal cells
Jawab : B
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
5. polypeptides
Jawab : C
6. Which of the following is the correct representation of the subunits of the acetylcholine (ACh) receptor at the neuromuscular junction? A. Alfa, Beta, gamma, delta B. Alfa2, Beta, Gamma, Delta C. Alfa, Beta2, Gamma, Delta D. Alfa, Beta, Gamma2, Delta E. Alfa, Beta, Gamma, Delta2
Jawab : B
- Which of the following is true of the a subunit of the nicotinic acetylcholine receptor?
A. It contains four hydrophobic transmembrane portions.
B. The binding site is not located on the a 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.
Jawab : A
The binding site is located on the beta subunit, the trans membrane segment is the most highly conserved, and the cytoplasmic loop connecting M3 and M4 is the least highly conserved. Both the N- and the C-terminalsare extracellular. Response A is correct.
8. The number of binding sites on the nicotinic acetylcholine receptor is A. 1 B. 2 C. 3 D. 4 E. 5
Jawab : B
For questions 9 and 10, match the description with the receptor. A. Alfa Subunit of GABA receptor B. Beta subunit of GABA receptor C. Both D. Neither 9. binds y-aminobutyric acid (GABA)
Jawab : C
For questions 9 and 10, match the description with the receptor. A. Alfa Subunit of GABA receptor B. Beta subunit of GABA receptor C. Both D. Neither 10. binds benzodiazepines
Jawab : A
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 (S-HT) receptor
11. most closely linked with synaptic pfasticity and cell death
Jawab : B
For questions 11-16 see Hall pp. 97-99. The N-methyl-D-aspartate (NMDA) receptor is voltage regulated in that the open channel is occluded at normal resting potential by Mg2+.Depolarization drives ~ g *o+ut of the cell, allowing other ions to pass.
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 (S-HT) receptor
12. GABA and this receptor are permeable to chloride ions.
Jawab : C
For questions 11-16 see Hall pp. 97-99. The N-methyl-D-aspartate (NMDA) receptor is voltage regulated in that the open channel is occluded at normal resting potential by Mg2+.Depolarization drives ~ g *o+ut of the cell, allowing other ions to pass.
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 (S-HT) receptor 13. binds strychnine
Jawab : C
For questions 11-16 see Hall pp. 97-99. The N-methyl-D-aspartate (NMDA) receptor is voltage regulated in that the open channel is occluded at normal resting potential by Mg2+.Depolarization drives ~ g *o+ut of the cell, allowing other ions to pass.
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 (S-HT) receptor 14. binds benzodiazepine
Jawab : A
For questions 11-16 see Hall pp. 97-99. The N-methyl-D-aspartate (NMDA) receptor is voltage regulated in that the open channel is occluded at normal resting potential by Mg2+.Depolarization drives ~ g *o+ut of the cell, allowing other ions to pass.
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 (S-HT) receptor
15. One type of this receptor is both ligand and voltage regulated
Jawab : B
For questions 11-16 see Hall pp. 97-99. The N-methyl-D-aspartate (NMDA) receptor is voltage regulated in that the open channel is occluded at normal resting potential by Mg2+.Depolarization drives ~ g *o+ut of the cell, allowing other ions to pass.
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 (S-HT) receptor
16. One type of this receptor is blocked by magnesium ions.
Jawab : B
For questions 11-16 see Hall pp. 97-99. The N-methyl-D-aspartate (NMDA) receptor is voltage regulated in that the open channel is occluded at normal resting potential by Mg2+.Depolarization drives ~ g *o+ut of the cell, allowing other ions to pass.
- significantly permeable to calcium ions
Jawab : B
- permeable to monovalent cations
Jawab : E
- ligand-gated
Jawab : E
- voltage-gated
Jawab : B
- blocked by magnesium ions
Jawab : B
- 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
Jawab : B
23. Pro-opiomelanocortin is a precursor of I. adrenocorticotropic hormone (ACTH) II. a-melanocyte-stimulating hormone (MSH) III. 13-endorphin IV. 13-lipotropin A. I, II, III B. I, III C. II, IV D. IV E. all of the above
Jawab : E
Pro-opiomelanocortin gives rise to adrenocorticotropic hormone (ACTH)and p-lipotropin. ACTH then gives rise to a-melanocyte-stimulatinghor- mone (a-MSH)and corticotropin-likeintermediate lobe peptide (CLIP),and p- lipotropin gives rise to y-lipotropin and p-endorphin.
- Removal of caicium 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
Jawab : A
Reversal of flow through voltage-gated channels is not a mecha- nism of removal of Ca2+fromthe cytosol.
- 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-ds retinal to all-trans retinal.
E. The decreased concentration of cGMP results in depolarization of the plasma membrane.
Jawab : E
The decreased concentration of cyclic guanosine monophosphate (cGMP)results in decreased current through the Na+channel and consequent hyperpolarization.
- 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 a subunit binds guanosine triphosphate (GTP).
D. The 13 and y subunits help anchor the a subunit to the plasma membrane.
E. The 13 and y subunits modulate guanosine diphosphate (GDP)/GTP exchange.
Jawab : A
Each G protein may be regulated by separate receptors.
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
Jawab : C
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 28. increased by nitric oxide
Jawab : D
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 29. hydrolyzed by phospholipase C
Jawab : E
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
30. synergistically activates protein kinase C with calcium
Jawab : A
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 31. binds to calmodulin
Jawab : A
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
32. Photoreception utilizes this second messenger.
Jawab : D
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
33. opens a calcium channel in the endoplasmic reticulum, releasing free calcium into the cytosol
Jawab : E
- 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
Jawab : E
The Na+/K+pump uses one molecule of adenosine triphosphate (ATP)for every three Na+ions transported.
- Each of the following is true of events occurring during the action potential except
A. 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 higherthan 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.
Jawab : B
Chloride permeability does not change during the action potential.
- 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
Jawab : B
- 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.
Jawab : D
For questions 38 to 40, match the description with the potential.
A. end-plate potential
B. miniature (!Ild-plate potential
C. both
D. neither
38. usually depolarizes muscle cells past threshold
Jawab : A
Miniature end-plate potentials result from random release of quanta of acetylcholine but do not produce an action potential.
For questions 38 to 40, match the description with the potential. A. end-plate potential B. miniature (!Ild-plate potential C. both D. neither 39. occurs in unstimulated cells
Jawab : D
Miniature end-plate potentials result from random release of quanta of acetylcholine but do not produce an action potential.
For questions 38 to 40, match the description with the potential.
A. end-plate potential
B. miniature (!Ild-plate potential
C. both
D. neither
40. produces a miniature action potential
Jawab : B
Miniature end-plate potentials result from random release of quanta of acetylcholine but do not produce an 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+orCl- E. Na+or K+
Jawab : B
- 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.
Jawab : A
Dynamin uses GTP as an energy source. Dynein is the motor protein for retrograde fast axonal transport. Slow axonal transport occurs at several millimeters per day; fast axonal transport occurs a t 200 to 400 mm/day and utilizes microtubules.
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.
Jawab : C
For questions 43 to 52, match the description with the structure.
A. Golgi’s tendon organ
B. muscle spindle
C. both
D. neither
44. Discharge increases with active contraction.
Jawab : A
For questions 43 to 52, match the description with the structure. A. Golgi's tendon organ B. muscle spindle C. both D. neither 45. in series with extrafusal fibers
Jawab : A
For questions 43 to 52, match the description with the structure. A. Golgi's tendon organ B. muscle spindle C. both D. neither 46. in parallel with extrafusal fibers
Jawab : B
For questions 43 to 52, match the description with the structure. A. Golgi's tendon organ B. muscle spindle C. both D. neither 47. sensitive to muscle tension
Jawab : B
For questions 43 to 52, match the description with the structure.
A. Golgi’s tendon organ
B. muscle spindle
C. both
D. neither
48. sensitive to muscle length and velocity of length change
Jawab : B
For questions 43 to 52, match the description with the structure.
A. Golgi’s tendon organ
B. muscle spindle
C. both
D. neither
49. innervated by group I (large myelinated) fibers
Jawab : C
For questions 43 to 52, match the description with the structure.
A. Golgi’s tendon organ
B. muscle spindle
C. both
D. neither
50. innervated by group II (small myelinated) fibers
Jawab : B
For questions 43 to 52, match the description with the structure.
A. Golgi’s tendon organ
B. muscle spindle
C. both
D. neither
51. Conduction velocity of afferent fibers is > 120 m/s.
Jawab : D
For questions 43 to 52, match the description with the structure.
A. Golgi’s tendon organ
B. muscle spindle
C. both
D. neither
52. contains dynamic nuclear bag, static nuclear bag, and nuclear chain fibers
Jawab : B
- 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.
Jawab : C
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.
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
Jawab : C
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 55. has phasic and tonic components
Jawab : F
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 56. a protective reflex involving polysynaptic reflex pathways
Jawab : B
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 57. the electrical equivalent of the tendon reflex
Jawab : D
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 58. the direct motor response obtained by stimulating a mixed motor-sensory nerve
Jawab : E
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 59. A length-dependent change in muscle force when the limb is passively moved
Jawab : A
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 Jawab : B
Jawab : B
- 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.
Jawab : C
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.
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
Jawab : B
Carbon dioxide and volatile anesthetic agents increase cerebrospinal fluid (CSF) production, whereas carbonic anhydrase inhibitors and norepineph- rine inhibit CSF productio
63. The main neurotransmitter of the Renshaw cell is thought to be A. acetylcholine B. GABA C. glutamate D. glycine E. histamine
Jawab : D
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
Jawab : A
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 65. cochlear nuclei
Jawab : B
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 66. inferior colliculus
Jawab : E
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 67. lateral lemniscus
Jawab : D
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 68. superior olivary nucleus
Jawab : C
- Absence or delay implies cervical cord disease.
Jawab : B
- Absence or delay implies peripheral nerve disease.
Jawab : A
- Absence or delay implies a lesion in the lower medulla.
Jawab : C
- is found at the shoulder
Jawab : A
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/lOO g/min
B. 55 mL/100 g/min
C. 23 mL/100 g/min
D. 17 mL/100 g/min
E. 8 mL/lOO g/min
73. critical threshold below which functional impairment occurs
Jawab : C
The state of hypoperfusion between a cerebral blood flow of 8 and 23 mL/100g/min is known as the ischemic 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.
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/lOO g/min
B. 55 mL/100 g/min
C. 23 mL/100 g/min
D. 17 mL/100 g/min
E. 8 mL/lOO g/min
74. Irreversible infarction occurs below this flow rate.
Jawab : E
The state of hypoperfusion between a cerebral blood flow of 8 and 23 mL/100g/min is known as the ischemic 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.
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/lOO g/min B. 55 mL/100 g/min C. 23 mL/100 g/min D. 17 mL/100 g/min E. 8 mL/lOO g/min 75. normal cerebral blood flow
Jawab : B
The state of hypoperfusion between a cerebral blood flow of 8 and 23 mL/100g/min is known as the ischemic 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.
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.
Jawab : C
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; utilizeglutamate),afewGolgi’scells,andglomeruli(wherecellsinthegranular 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.
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
77. reside in the granular layer together with granule cells
Jawab : B
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; utilizeglutamate),afewGolgi’scells,andglomeruli(wherecellsinthegranular 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.
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 78. excitatory
Jawab : C
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; utilizeglutamate),afewGolgi’scells,andglomeruli(wherecellsinthegranular 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.
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 79. Mossy fibers synapse here.
Jawab : C
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; utilizeglutamate),afewGolgi’scells,andglomeruli(wherecellsinthegranular 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.
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 80. Climbing fibers synapse here.
Jawab : D
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; utilizeglutamate),afewGolgi’scells,andglomeruli(wherecellsinthegranular 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.
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 81. the only cerebellar cortical output
Jawab : D
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; utilizeglutamate),afewGolgi’scells,andglomeruli(wherecellsinthegranular 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.
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
82. directly inhibit Purkinje’s cells together with stellate cells
Jawab : A
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; utilizeglutamate),afewGolgi’scells,andglomeruli(wherecellsinthegranular 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.
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 83. utilize glutamate
Jawab : C
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; utilizeglutamate),afewGolgi’scells,andglomeruli(wherecellsinthegranular 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.
- 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.
Jawab : A
85. The sensation of sharp, pricking pain is mediated by A. A alfa fibers B. A beta fibers C. A Gamma Fibers D. A delta fibers E. C fibers
Jawab : D
- 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.
Jawab : D
Unlike the ACh receptors at the neuromuscularjunction, theAChreceptorsinautonomicgangliacontainonly two types of subunits. The fast excitatory postsynaptic potential (EPSP) is mediated by nicotinic ACh receptors, the slow EPSP is mediated by mus- carinic 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 modu- latory in action may be co-released with ACh.
- 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.
Jawab : A
Increased sympathetic activity results in bladder wall relaxation.
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 ofthe above
Jawab : B
89. Ipsilateral corticocortical association fibers arise from cells in cortical layers A. I and II B. II and III C. III and IV D. IVandV E. V and VI
Jawab : B
- 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.
Jawab : C
- 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.
Jawab : B
Renshaw cells inhibit la inhibitory interneurons that act on antagonist motor neurons.
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
Jawab : B
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 facili- tatory 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.
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
93. This nucleus and the medial vestibular nucleus are involved in mediating vestibulo-ocular reflexes.
Jawab : D
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 facili- tatory 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.
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 94. also known as Deiters' nucleus
Jawab : B
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 facili- tatory 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.
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
95. integrates input from the vestibular labyrinth and the cerebellum
Jawab : A
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 facili- tatory 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.
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
96. Decerebrate rigidity is due to the unopposed excitatory effect of the reticulospinal tract and the tract originating from this nucleus
Jawab : B
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 facili- tatory 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.
97. Which of the following modifications of proteins does not occur in the Golgi's complex? A. attachment offatty acids B. formation of O-Iinked sugars C. initiation of N-Iinked glycosylation D. sugar phosphorylation E. sulfation of tyrosine residues
Jawab : C
The initial steps of N-linked glycosylation take place in the endoplasmic reticulum.
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. a-bungarotoxin
Jawab : A
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
99. botulinum
Jawab : G
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
100. cholera
Jawab : F
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
- cocaine
Jawab : B
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
102. reserpine
Jawab : E
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
103. tetraethylammonium (TEA)
Jawab : C
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
104. tetrodotoxin
Jawab : D
- 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
Jawab : A
At the equilibrium potential, the chemical and electrical forces are equal. There is no net movement of K ions across the membrane.
- 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 GOP inactivates a G protein.
C. The Beta-gamma subunit stabilizes the binding of GOP.
D. The Beta-gamma subunit stabilizes the binding of GTP.
E. When activated, the a subunit’s affinity for the Beta-gamma subunit decreases.
Jawab : D
The py subunit inhibits activation by both stabilizing the binding of GDP and inhibiting the binding of GTP.
- 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
Jawab : C
Succinylcholine and decamethonium cause depolarizing neuromuscular blockade. The effect is not reversed by anticholinesterase agents and is amplified by decreased muscle temperature.
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
Jawab : C
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
109. pressure and joint position in deep tissue
Jawab : B
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
110. slowly and rapidly adapting receptors in the skin
Jawab : D
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
111. rapidly adapting receptors in the skin
Jawab : A
- Each of the following is true of the dorsal-column mediallemniscal 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 (S I).
D. Thalamic neurons project to the secondary somatic sensory cortex (S II).
E. Touch and vibration sense from the arm is relayed in the dorsal columns.
Jawab : A
Proprioception from the leg is relayed in the lateral column by axons of neurons in Clarke’s column. In addition to sending axons to the primarysomaticsensorycortex(St),thalamicneuronssendasparseprojection to the secondary somatic sensory cortex (SII).
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
Jawab : D
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
114. appendicular ataxia
Jawab : A
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
115. terminal tremor
Jawab : B
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
116. nystagmus
Jawab : C
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
117. scanning speech
Jawab : D
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
118. hypertonia
Jawab : E
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
119. Hypotonia is seen in lesions of the interposed nuclei or of this portion.
Jawab : D
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
120. decomposition of multijoint movements
Jawab : B
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
121. delay in initiating movements
Jawab : B
122. In the formation of nitric oxide, nitric oxide synthetase acts on the substrate A. arginine B. citrulline C. lysine D. ornithine E. tyrosine
Jawab : A
Nitric oxide production in neurons is from L-arginine by nitric oxide synthetase acting in conjunction with the cofactor, reduced nicotinamide adenine dinucleotide phosphate (NADPH), and Ca2+ions. The arginine is converted to citrulline.
123. The pineal gland synthesizes melatonin from A. acetylcholine B. dopamine C. histidine D. norepinephrine E. serotonin
Jawab : E
he pineal gland synthesizes melatonin from serotonin by the action of two enzymes sensitive to variations of diurnal light. The rhythmic fluctuations in melatonin synthesis are directly related to the daily light cycle
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
Jawab : C
The nicotinic and muscarinic receptors both bind acetylcholine and are found in sympathetic neurons, whereas the directly gated receptors in skeletal muscle are muscarinic. Hexamethonium selectively blocks nicotinic ACh receptors. Muscarinic receptors activate a second messenger system that closes a K+ channel (called the M channel).
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 125. found in skeletal muscle
Jawab : B
The nicotinic and muscarinic receptors both bind acetylcholine and are found in sympathetic neurons, whereas the directly gated receptors in skeletal muscle are muscarinic. Hexamethonium selectively blocks nicotinic ACh receptors. Muscarinic receptors activate a second messenger system that closes a K+ channel (called the M channel).
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 126. found in sympathetic neurons
Jawab : C
The nicotinic and muscarinic receptors both bind acetylcholine and are found in sympathetic neurons, whereas the directly gated receptors in skeletal muscle are muscarinic. Hexamethonium selectively blocks nicotinic ACh receptors. Muscarinic receptors activate a second messenger system that closes a K+ channel (called the M channel).
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 127. blocked by hexamethonium
Jawab : B
The nicotinic and muscarinic receptors both bind acetylcholine and are found in sympathetic neurons, whereas the directly gated receptors in skeletal muscle are muscarinic. Hexamethonium selectively blocks nicotinic ACh receptors. Muscarinic receptors activate a second messenger system that closes a K+ channel (called the M channel).
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
128. activates a second messenger system that closes a K+ channel
Jawab : A
The nicotinic and muscarinic receptors both bind acetylcholine and are found in sympathetic neurons, whereas the directly gated receptors in skeletal muscle are muscarinic. Hexamethonium selectively blocks nicotinic ACh receptors. Muscarinic receptors activate a second messenger system that closes a K+ channel (called the M channel).
129. The EPSP in spinal motor neurons results from the opening of A. CI- channels only B. CI- and Na+ channels C. K+ channels only D. Na+ and K+ channels E. Na+ and Cl- channels
Jawab : D
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
Jawab : E
For questions 131 to 137, match the description with the structure. A. thick filaments B. thin filaments C. both D. neither 131. contains actin
Jawab : B
For questions 131 to 137, match the description with the structure. A. thick filaments B. thin filaments C. both D. neither 132. contains myosin
Jawab : A
For questions 131 to 137, match the description with the structure. A. thick filaments B. thin filaments C. both D. neither 133. contains tropomysin
Jawab : B
For questions 131 to 137, match the description with the structure. A. thick filaments B. thin filaments C. both D. neither 134. contains troponin
Jawab : B
For questions 131 to 137, match the description with the structure. A. thick filaments B. thin filaments C. both D. neither 135. binds ADP during rest
Jawab : A
For questions 131 to 137, match the description with the structure. A. thick filaments B. thin filaments C. both D. neither 136. Sarcomeres contain them.
Jawab : C
For questions 131 to 137, match the description with the structure. A. thick filaments B. thin filaments C. both D. neither 131. contains actin Jawab : B 137. attached to the Z disks
Jawab : B
- 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.
Jawab : B
Duringskeletalmusclecontraction,calciumbindstotro- ponin. Both the association and detachment of cross bridges require ATP (not GTP). During relaxation, Ca2+is actively pumped out of the intracellular space and back into the sarcoplasmic reticulum.
139. The resting potential of a neuron is approximately A. -90mV B. -65mV C. -50 mV D. +50mV E. +65 mV
Jawab : B
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
Jawab : A
Alcohol decreases the release of ADH.
- 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.
Jawab : D
he enzymes that catalyze the synthesis of the low molec- ular weight transmitters are usually cytoplasmic (dopamine-p-hydroxylase is an exception),but this is not a criterion that must be fulfilled for a chemical to be considered a transmitter.
- Each of the following is considered a neurotransmitter except
A. epinephrine
B. glycine
C. histamin
D. serotonin
E. vasoactive intestinal polypeptide (VIP)
Jawab : E
VIP is considered a neuroactive peptide, not a neurotransmitter.
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
Jawab : E
The sweat glands are innervated by the sympathetic system only.
- 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.
Jawab : B
The activity of y motor neurons is profoundly reduced by lesions in the cerebellum.
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
Jawab : C
escending serotonergic pathways (from rostroventral medullary neurons) and noradrenergic pathways (fromthe pons) are impor- tant links in the supraspinal modulation of nociceptive transmission.
- Cell groups that have concentric receptive fields include
I. retinal ganglion cells
II. simple cells ofthe 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
Jawab : B
Cells of the retina and lateral geniculate nucleus have concentric receptive fields that fall into two classes: on-center or off-center. Simple cells of the visual cortex have rectangular receptive fields. The recep- tivefieldofacomplexcellintheprimaryvisualcortexhasnoclearlydistinct excitatory or inhibitory zones. Orientation but not position of the light stimu- lus is important.
For questions 147 to l5I, 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
- a subcutaneous, slowly adapting receptor
Jawab : E
Meissner’s corpuscles and Merkel’s receptors are both found superficially in the dermal papillae and have small receptive fields. Pacinian and Ruffini’s corpuscles are found in the deeper subcutaneous tissue and have large receptive fields. Both Merkel’s receptors and Ruffini’s corpuscles are slowly adapting and subserve pressure sensation. Pacinian corpuscles are more sensitive to low- than high-frequency stimuli and transmit flutter. Pain sensation is transmitted by free nerve endings.
- a rapidly adapting receptor found in the dermal papillae
Jawab : B
Meissner’s corpuscles and Merkel’s receptors are both found superficially in the dermal papillae and have small receptive fields. Pacinian and Ruffini’s corpuscles are found in the deeper subcutaneous tissue and have large receptive fields. Both Merkel’s receptors and Ruffini’s corpuscles are slowly adapting and subserve pressure sensation. Pacinian corpuscles are more sensitive to low- than high-frequency stimuli and transmit flutter. Pain sensation is transmitted by free nerve endings.
- a receptor subs erving pressure and with a small receptive field
Jawab : C
Meissner’s corpuscles and Merkel’s receptors are both found superficially in the dermal papillae and have small receptive fields. Pacinian and Ruffini’s corpuscles are found in the deeper subcutaneous tissue and have large receptive fields. Both Merkel’s receptors and Ruffini’s corpuscles are slowly adapting and subserve pressure sensation. Pacinian corpuscles are more sensitive to low- than high-frequency stimuli and transmit flutter. Pain sensation is transmitted by free nerve endings.
- a rapidly adapting receptor more sensitive to high-frequency stimulation than low-frequency stimulation
Jawab : D
Meissner’s corpuscles and Merkel’s receptors are both found superficially in the dermal papillae and have small receptive fields. Pacinian and Ruffini’s corpuscles are found in the deeper subcutaneous tissue and have large receptive fields. Both Merkel’s receptors and Ruffini’s corpuscles are slowly adapting and subserve pressure sensation. Pacinian corpuscles are more sensitive to low- than high-frequency stimuli and transmit flutter. Pain sensation is transmitted by free nerve endings.
- a nociceptor
Jawab : A
Meissner’s corpuscles and Merkel’s receptors are both found superficially in the dermal papillae and have small receptive fields. Pacinian and Ruffini’s corpuscles are found in the deeper subcutaneous tissue and have large receptive fields. Both Merkel’s receptors and Ruffini’s corpuscles are slowly adapting and subserve pressure sensation. Pacinian corpuscles are more sensitive to low- than high-frequency stimuli and transmit flutter. Pain sensation is transmitted by free nerve endings.
