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