NURS 371 PHARMACOLOGY QUESTIONS AND ANSWERS
LATEST UPDATE ALREADY GRADED A+
Which statement about Na+ permeability during an action potential is most accurate?
a.) It is long lasting.
b.) It is responsible for the rising phase of the action potential.
c.) It is responsible for the falling phase of the action potential.
d.) It restores the membrane potential to its usual level following the action potential.
b.) It is responsible for the rising phase of the action potential.
The voltage clamp method controls the _______ at any desired level.
Question options:
1) amplitude of an action potential
2) frequency of an action potential
3) membrane potential
4) K+ current
5) Na+ current
3) membrane potential
The classic voltage clamp technique would be suitable for which application?
a)Evaluation of effects of large intracellular molecules on the function of ion channel
b)Direct measurement of current flowing through the cell membrane
c)Measurement of current flowing through a single ion channel
d) Study of the ionic composition of the intracellular environment
b) Direct measurement of current flowing through the cell membrane
Which current corresponds to a flow of Na+ in response to a depolarizing stimulus in a giant axon of a
squid?
a) Transient inward current
b) Delayed outward current
c) Prolonged outward current
a.)Transient inward current
In voltage clamp experiments, the early current will disappear if the membrane is clamped at _______
mV.
Question options:
a.)-26
b)0
c)+ 26
d) +52
d.) +52
, Practically speaking, how would you determine that Na+ influx into a cell underlies the early current?
a)Replace intracellular Na+ with its radioactive form and trace its movement across the membrane.
b)Remove Na+ from the extracellular compartment and assess the early current under new
conditions.
c)Use the voltage clamp method to measure the current.
b)Remove Na+ from the extracellular compartment and assess the early current under new conditions.
Which conclusion can be drawn from Hodgkin and Huxley's studies of K+ and Na+ conductances?
a)Both conductances exhibit the property of time-dependent activation.
b)Both conductances depend on voltage.
c)K+ conductance reaches its maximum with a pronounced delay.
d)Unlike K+ conductance, Na+ conductance reaches its maximum and inactivates rapidly.
e)All of the above
e.) All of the above
An action potential travels in only one direction along the axon because of its _______ property.
a)refractory
b)all-or-none
c)passive
d)active
e)transient
a.) Refractory
Ion channels that are involved in generation of action potentials open or close in response to
a)voltage
b)neurotransmitters.
c)second messengers.
d)mechanical stimulation.
e) temperature.
a.) Voltage
In what way are ion channels similar to active transporters?
Question options:
a)Both are proteins.
b)Both actively move ions from one side of the membrane to the other.
c)Both create ion concentration gradients.
d)Both maintain ion concentration gradients.
e)Both enable selective ion permeability.
a.) Both are proteins
Which technique would you use to study the effects of the extracellular environment on ion channel
activity?
LATEST UPDATE ALREADY GRADED A+
Which statement about Na+ permeability during an action potential is most accurate?
a.) It is long lasting.
b.) It is responsible for the rising phase of the action potential.
c.) It is responsible for the falling phase of the action potential.
d.) It restores the membrane potential to its usual level following the action potential.
b.) It is responsible for the rising phase of the action potential.
The voltage clamp method controls the _______ at any desired level.
Question options:
1) amplitude of an action potential
2) frequency of an action potential
3) membrane potential
4) K+ current
5) Na+ current
3) membrane potential
The classic voltage clamp technique would be suitable for which application?
a)Evaluation of effects of large intracellular molecules on the function of ion channel
b)Direct measurement of current flowing through the cell membrane
c)Measurement of current flowing through a single ion channel
d) Study of the ionic composition of the intracellular environment
b) Direct measurement of current flowing through the cell membrane
Which current corresponds to a flow of Na+ in response to a depolarizing stimulus in a giant axon of a
squid?
a) Transient inward current
b) Delayed outward current
c) Prolonged outward current
a.)Transient inward current
In voltage clamp experiments, the early current will disappear if the membrane is clamped at _______
mV.
Question options:
a.)-26
b)0
c)+ 26
d) +52
d.) +52
, Practically speaking, how would you determine that Na+ influx into a cell underlies the early current?
a)Replace intracellular Na+ with its radioactive form and trace its movement across the membrane.
b)Remove Na+ from the extracellular compartment and assess the early current under new
conditions.
c)Use the voltage clamp method to measure the current.
b)Remove Na+ from the extracellular compartment and assess the early current under new conditions.
Which conclusion can be drawn from Hodgkin and Huxley's studies of K+ and Na+ conductances?
a)Both conductances exhibit the property of time-dependent activation.
b)Both conductances depend on voltage.
c)K+ conductance reaches its maximum with a pronounced delay.
d)Unlike K+ conductance, Na+ conductance reaches its maximum and inactivates rapidly.
e)All of the above
e.) All of the above
An action potential travels in only one direction along the axon because of its _______ property.
a)refractory
b)all-or-none
c)passive
d)active
e)transient
a.) Refractory
Ion channels that are involved in generation of action potentials open or close in response to
a)voltage
b)neurotransmitters.
c)second messengers.
d)mechanical stimulation.
e) temperature.
a.) Voltage
In what way are ion channels similar to active transporters?
Question options:
a)Both are proteins.
b)Both actively move ions from one side of the membrane to the other.
c)Both create ion concentration gradients.
d)Both maintain ion concentration gradients.
e)Both enable selective ion permeability.
a.) Both are proteins
Which technique would you use to study the effects of the extracellular environment on ion channel
activity?
