Pregunta 1
Pregunta
In synaptic integration, summation can take place between:
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IPSPs and other IPSPs but temporal summation only
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IPSPs and other IPSPs or EPSPs both temporal and spatial summation
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EPSPs and other EPSPs but spatial summation only.
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choices 1 and 2
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choices 1, 2 and 3
Pregunta 2
Pregunta
During plateau action potential:
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the delayed rectifier channels are fully open
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the inward rectifier channels are closed
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the Ca2+ channels are open
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choices 1 and 2
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choices 2 and 3
Pregunta 3
Pregunta
About after-potentials of an action potential evoked following repetitive activity:
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the after-depolarization is partly due to slowing down of K+ efflux
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the after-hyperpolarization is partly due to excessive extrusion of Na+ by the pump.
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the after-hyperpolarization is partly due to excessive efflux of K+
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choices 1 and 2
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choices 1, 2 and 3
Pregunta 4
Pregunta
About transport within neuron: particles can be transported within the cytoplasm:
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from the nerve terminals to the cell body and is called retrograde.
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from the cell body to the nerve endings and is called orthodromic.
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from the nerve terminals to the cell body and is called antidromic.
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choices 1 and 2
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choices 1, 2 and 3
Pregunta 5
Pregunta
The Na+-K+ transporter:
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pumps 3 Na+ out and 2 K+ in through their respective channels
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creates an increase in the negativity of the RMP
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is a form of secondary active transport
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choices 1 and 3 are true
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none of the above choices are true
Pregunta 6
Pregunta
Amyotrophic lateral sclerosis (ALS):
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lesions are more localized whereas those of multiple sclerosis (MS) are diffused
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like MS, it demyelinate nerves only in the CNS
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like MS, may lead to paralysis
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choices 1 and 2
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choices 1, 2 and 3
Pregunta 7
Pregunta
The resting membrane potential of a nerve becomes:
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less negative when Na+ concentration in extracellular fluid [Na]o is increased
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less negative when [K+]o is increased
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more negative when [Na+]o is increased
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more negative when [Ca2+]o is increased
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none of the above
Pregunta 8
Pregunta
If the K+ delayed rectifier channels are blocked by TEA then the nerve AP would:
Pregunta 9
Pregunta
The nerve action potential:
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during its up-stroke the Na+/K+ permeability ratio is small
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during its down-stroke (repolarization), the K+/Na+ permeability ratio is small
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its upstroke is due to Na+ activation
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choices 1 and 2
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choices 2 and 3
Pregunta 10
Pregunta
The compound action potential:
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cannot be recorded form a single squid giant axon
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is not an all-or-none response
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can be only be recorded in the PNS
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choices 1 and 2.
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choices 1, 2 and 3.
Pregunta 11
Pregunta
The resting membrane potential:
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supplies “potential energy” for firing action potentials
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can be calculated by using a modified Nernst equation
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supplies needed energy for the Na-K pump
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choices 1 and 2
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choices 1,2 and 3
Pregunta 12
Pregunta
Subthreshold depolarization of the axon membrane
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remains the same size at each point along the axon membrane
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produces a local response
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decreases in size as it sweeps along the membrane
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choices 1 and 2
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choices 2 and 3
Pregunta 13
Pregunta
In a myelinated axon, at which point along the axon can ion enter and leave the membrane?
Pregunta 14
Pregunta
Which of the following is an advantage of salutatory conduction?
Pregunta 15
Pregunta
The essential event (s) for the release of neurotransmitter from presynaptic membrane is:
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the arrival of an EPSP at the axon terminal
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influx of calcium ions into the axon terminal
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influx of K ions into the axon terminal
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choices 1 and 2
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choices 1, 2 and 3
Pregunta 16
Pregunta
Presynaptic inhibition
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can be produced by chloride efflux at certain nerve terminals
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it may involve AMPA receptors
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longer lasting than postsynaptic inhibition
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choices 1 and 2
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choices 1 and 3
Pregunta 17
Pregunta
Which of the following will produce an EPSP?
Pregunta 18
Pregunta
Which of the following is true
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oligodendrocytes exist in the brain
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Schwann cells provide myelin for peripheral nerve axons
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a single Schwann cell wraps a single segment of a peripheral nerve
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a single oligodendrocytes can mylinate up to 50 segments of axon membrane
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all of the above are correct
Pregunta 19
Pregunta
_________ generate scar tissue which impedes regeneration of damaged axons
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astrocytes
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Schwann cells
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axon terminals
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oligodendrocytes
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dendrites
Pregunta 20
Pregunta
Which of the following represents the normal order of activation in neuronal transmission?
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axon∏ dendrites∏soma∏axon terminals
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axon terminals ∏soma∏ axon∏ dendrites
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dendrites∏soma∏ axon∏ axon terminals
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soma∏ axon∏ dendrites∏axon terminals
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dendrites∏ axon terminals∏ soma∏ axon
Pregunta 21
Pregunta
The ___________ is defined as the difference in electrical charge between the intracellular side and the extracellular side of an inactive nerve cell membrane.
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local potential
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EPSP
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action potential
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membrane potential
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EPP
Pregunta 22
Pregunta
An electric stimulus applied to an axon that moves the membrane potential from –70 to –45 mV will result in:
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local potential
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EPSP
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action potential
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membrane potential
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EPP
Pregunta 23
Pregunta
Match the correct synaptic event with each ion channel action:
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entry of a negative ion-hyperpolarization
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entry of a positive ion-hyperpolarization
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exit of a positive ion-depolarization
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exit of a negative ion-hyperpolarization
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choices 1 and 3 are correct
Pregunta 24
Pregunta
Which of the following events contribute to the restoration of the membrane potential from the peak of action potential
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closure of sodium channels
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potassium ions move out of the cell
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the sodium-potassium transporter
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choices 1 and 2
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choices 1, 2 and 3
Pregunta 25
Pregunta
Regarding types of synaptic transmission: _______ is an example of ________
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glutamate NMDA receptor-fast synaptic transmission
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mACh receptor-fast synaptic transmission
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serotonin 5-HT3 receptor-slow synaptic transmission
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GABAa receptor-slow synaptic transmission
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all of the above correct correct
Pregunta 26
Pregunta
Compared with types A and B fibers; type C fibers are:
Pregunta 27
Pregunta
Sodium channels, K channels and Na-K pumps exist on all parts of:
Pregunta 28
Pregunta
The process that blocks all postsynaptic potentials is:
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blockade of the postsynaptic receptors.
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inhibition of transmitter release.
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degradation of the transmitter molecule by a native enzyme.
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choices 1 and 2
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choices 1, 2 and 3
Pregunta 29
Pregunta
The “all-or-none law”:
Pregunta 30
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Are involved directly in the production of action potential
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cross the membrane through their specific channels during action potential by simple diffusion
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responsible for formation of EPP
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choices 1 and 2
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choices 2 and 3
Pregunta 31
Pregunta
Which of the following will "neutralize" an EPSP?
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further opening a sodium channel
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allowing intracellular anions to leave the cell
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closing a potassium channel
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opening a chloride channel
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choices 2 and 4.
Pregunta 32
Pregunta
Which of the following statements is correct?
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CO2 and O2 are not lipid soluble substances.
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Some drugs (e.g. endomethacin) stabilize lysosomal membrane, which may explain their anti-
inflammatory action
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specific Na+ channels are the same as acetylcholine channels.
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Fast axonal transport is directly involved in conduction of impulses.
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All of the above are incorrect.
Pregunta 33
Pregunta
Which of the following will produce an IPSP?
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opening sodium channels only
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opening chloride channels only
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opening potassium channels only
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choices 1 and 2
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choices 2 and 3
Pregunta 34
Pregunta
The membranes that most commonly form synapses are the ______ and _______
Pregunta 35
Pregunta
About the reversal potential of a nerve:
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different excitable tissues have different reversal potentials
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it is the highest positive value the AP reaches
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is also called the threshold
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choices 1 and 2
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choices 2 and 3
Pregunta 36
Pregunta
What type of refractory periods occurs during:
Pregunta 37
Pregunta
The process which terminates the action of ACh at the neuromuscular junction is:
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disruption of the postsynaptic receptor.
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enzymatic degradation by ACh-esterases.
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inhibition of ACh synthesis.
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choices 1 and 2
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choices 1, 2 and 3
Pregunta 38
Pregunta
A drug that opens potassium channels of an axon and causes a 5 mV change in resting membrane potential (RMP):
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that change is called depolarization
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causes a 5 mV increase in the amplitude of evoked action potential
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that change is called hyperpolarization
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choices 1 and 2
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choices 2 and 3
Pregunta 39
Pregunta
Conduction velocity of a nerve can be calculated if the following information is provided:
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duration of action potentials (AP) and length of nerve
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the latent period and length of nerve between electrodes
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strength of the stimulus and length of nerve
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the refractory periods and length of nerve
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none of the above, more information is needed.
Pregunta 40
Pregunta
Which of the following statement(s) about compound action potential is/are False?
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Compound action potential is seen when a single axon is stimulated
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The first peak in a compound action potential belongs to A fiber type
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A compound action potential is an all-or-none phenomenon
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choices 1 and 2
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choices 1 and 3