Practice Exam 1

Question 1 of 40

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In synaptic integration, summation can take place between:

Select one of the following:

  • IPSPs and other IPSPs but temporal summation only

  • IPSPs and other IPSPs or EPSPs both temporal and spatial summation

  • EPSPs and other EPSPs but spatial summation only.

  • choices 1 and 2

  • choices 1, 2 and 3

Question 2 of 40

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During plateau action potential:

Select one of the following:

  • the delayed rectifier channels are fully open

  • the inward rectifier channels are closed

  • the Ca2+ channels are open

  • choices 1 and 2

  • choices 2 and 3

Question 3 of 40

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About after-potentials of an action potential evoked following repetitive activity:

Select one of the following:

  • the after-depolarization is partly due to slowing down of K+ efflux

  • the after-hyperpolarization is partly due to excessive extrusion of Na+ by the pump.

  • the after-hyperpolarization is partly due to excessive efflux of K+

  • choices 1 and 2

  • choices 1, 2 and 3

Question 4 of 40

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About transport within neuron: particles can be transported within the cytoplasm:

Select one of the following:

  • from the nerve terminals to the cell body and is called retrograde.

  • from the cell body to the nerve endings and is called orthodromic.

  • from the nerve terminals to the cell body and is called antidromic.

  • choices 1 and 2

  • choices 1, 2 and 3

Question 5 of 40

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The Na+-K+ transporter:

Select one of the following:

  • pumps 3 Na+ out and 2 K+ in through their respective channels

  • creates an increase in the negativity of the RMP

  • is a form of secondary active transport

  • choices 1 and 3 are true

  • none of the above choices are true

Question 6 of 40

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Amyotrophic lateral sclerosis (ALS):

Select one of the following:

  • lesions are more localized whereas those of multiple sclerosis (MS) are diffused

  • like MS, it demyelinate nerves only in the CNS

  • like MS, may lead to paralysis

  • choices 1 and 2

  • choices 1, 2 and 3

Question 7 of 40

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The resting membrane potential of a nerve becomes:

Select one of the following:

  • less negative when Na+ concentration in extracellular fluid [Na]o is increased

  • less negative when [K+]o is increased

  • more negative when [Na+]o is increased

  • more negative when [Ca2+]o is increased

  • none of the above

Question 8 of 40

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If the K+ delayed rectifier channels are blocked by TEA then the nerve AP would:

Select one of the following:

  • look similar to the cardiac ventricular AP

  • look like a pacemaker AP

  • be blocked

  • look like a skeletal muscle AP

  • none of the above

Question 9 of 40

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The nerve action potential:

Select one of the following:

  • 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

  • choices 1 and 2

  • choices 2 and 3

Question 10 of 40

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The compound action potential:

Select one of the following:

  • cannot be recorded form a single squid giant axon

  • is not an all-or-none response

  • can be only be recorded in the PNS

  • choices 1 and 2.

  • choices 1, 2 and 3.

Question 11 of 40

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The resting membrane potential:

Select one of the following:

  • supplies “potential energy” for firing action potentials

  • can be calculated by using a modified Nernst equation

  • supplies needed energy for the Na-K pump

  • choices 1 and 2

  • choices 1,2 and 3

Question 12 of 40

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Subthreshold depolarization of the axon membrane

Select one of the following:

  • 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 of 40

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In a myelinated axon, at which point along the axon can ion enter and leave the membrane?

Select one of the following:

  • the membrane segment under the Schwann cell wrapping

  • the axon hillock

  • the node of Rnavier

  • choices 1 and 2

  • choices 2 and 3

Question 14 of 40

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Which of the following is an advantage of salutatory conduction?

Select one of the following:

  • faster conduction

  • less transmitter is required to send a message across the synapse

  • conservation of energy: i.e. less energy is expended by the membrane

  • choices 1 and 2

  • choices 1 and 3

Question 15 of 40

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The essential event (s) for the release of neurotransmitter from presynaptic membrane is:

Select one of the following:

  • 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 of 40

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Presynaptic inhibition

Select one of the following:

  • 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 of 40

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Which of the following will produce an EPSP?

Select one of the following:

  • opening sodium channels

  • closing sodium channels

  • opening potassium channels

  • opening chloride channels

  • closing calcium channels

Question 18 of 40

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Which of the following is true

Select one of the following:

  • oligodendrocytes exist in the brain

  • Schwann cells provide myelin for peripheral nerve axons

  • a single Schwann cell wraps a single segment of a peripheral nerve

  • a single oligodendrocytes can mylinate up to 50 segments of axon membrane

  • all of the above are correct

Question 19 of 40

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_________ generate scar tissue which impedes regeneration of damaged axons

Select one of the following:

  • astrocytes

  • Schwann cells

  • axon terminals

  • oligodendrocytes

  • dendrites

Question 20 of 40

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Which of the following represents the normal order of activation in neuronal transmission?

Select one of the following:

  • axon∏ dendrites∏soma∏axon terminals

  • axon terminals ∏soma∏ axon∏ dendrites

  • dendrites∏soma∏ axon∏ axon terminals

  • soma∏ axon∏ dendrites∏axon terminals

  • dendrites∏ axon terminals∏ soma∏ axon

Question 21 of 40

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The ___________ is defined as the difference in electrical charge between the intracellular side and the extracellular side of an inactive nerve cell membrane.

Select one of the following:

  • local potential

  • EPSP

  • action potential

  • membrane potential

  • EPP

Question 22 of 40

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An electric stimulus applied to an axon that moves the membrane potential from –70 to –45 mV will result in:

Select one of the following:

  • local potential

  • EPSP

  • action potential

  • membrane potential

  • EPP

Question 23 of 40

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Match the correct synaptic event with each ion channel action:

Select one of the following:

  • 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 of 40

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Which of the following events contribute to the restoration of the membrane potential from the peak of action potential

Select one of the following:

  • 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 of 40

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Regarding types of synaptic transmission: _______ is an example of ________

Select one of the following:

  • 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 of 40

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Compared with types A and B fibers; type C fibers are:

Select one of the following:

  • unmyelinated

  • with the slowest speed of conducttion

  • sensitive to the action of local anesthetics

  • choices 1 and 2

  • choices 1, 2 and 3

Question 27 of 40

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Sodium channels, K channels and Na-K pumps exist on all parts of:

Select one of the following:

  • myelinated nerve membrane

  • unmyelinated nerve membrane

  • muscle cell membrane

  • choices 1 and 2

  • choices 2 and 3

Question 28 of 40

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The process that blocks all postsynaptic potentials is:

Select one of the following:

  • 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 of 40

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The “all-or-none law”:

Select one of the following:

  • does not apply to ventricular action potential

  • refers to the observation that an action potential is evoked whenever the membrane potential reaches threshold

  • does not apply to IPSP

  • choices 1 and 2

  • choices 1, 2 and 3

Question 30 of 40

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Sodium ions:

Select one of the following:

  • 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 of 40

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Which of the following will "neutralize" an EPSP?

Select one of the following:

  • 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 of 40

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Which of the following statements is correct?

Select one of the following:

  • 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 of 40

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Which of the following will produce an IPSP?

Select one of the following:

  • opening sodium channels only

  • opening chloride channels only

  • opening potassium channels only

  • choices 1 and 2

  • choices 2 and 3

Question 34 of 40

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The membranes that most commonly form synapses are the ______ and _______

Select one of the following:

  • motor nerve terminals ; skeletal muscle

  • axon terminals; dendrites

  • axon terminals; glial

  • choices 1 and 2

  • choices 1, 2 and 3

Question 35 of 40

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About the reversal potential of a nerve:

Select one of the following:

  • 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 of 40

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What type of refractory periods occurs during:

Select one of the following:

  • EPP- relative

  • EPSP-absolute

  • mEPP-realtive

  • mEPSP-absolute

  • none of the above is correct

Question 37 of 40

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The process which terminates the action of ACh at the neuromuscular junction is:

Select one of the following:

  • 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 of 40

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A drug that opens potassium channels of an axon and causes a 5 mV change in resting membrane potential (RMP):

Select one of the following:

  • 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 of 40

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Conduction velocity of a nerve can be calculated if the following information is provided:

Select one of the following:

  • 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 of 40

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Which of the following statement(s) about compound action potential is/are False?

Select one of the following:

  • 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

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Practice Exam 1

Justin Miller
Quiz by , created about 1 year ago

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Justin Miller
Created by Justin Miller about 1 year ago
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