PhysioEx Exercise 3 Test Answers

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When the stimulus intensity increases, _______.
the number of action potentials increases
In this activity, which of the following will increase the stimulus intensity?
increasing the duration of the stimulus
At threshold, axons will _______.
Likely generate an action potential if refractory periods have elapsed.
Longer stimuli will allow for _______.
more action potentials to occur, the absolute refractory period to finish and the relative refractory period to finish
The time interval between action potentials is called the _______.
interspike interval
Increase in stimulus intensity _______.
increases the frequency of action potentials
The frequency of action potentials is _______.
the reciprocal of the interspike interval, and measured in hertz
During the relative refractory period, _______.
the stimulus must be above threshold to generate an action potential
Which of the following occurs first in the generation of an action potential?
The membrane depolarizes
Which of the following occurs during depolarization?
Sodium flows into the cell
Which of the following occurs during repolarization?
Voltage-gated potassium channels open and some voltage-gated sodium channels inactivate. Potassium flows out of the cell
Which of the following allow the movement of potassium through the neuronal membrane?
leakage channels and voltage-gated potassium channels
Why does the threshold increase when the interval between the stimuli decreases?
Some sodium channels have been inactivated and cannot be reopened immediately
During the relative refractory period, _______.
another action potential can be generated provided the stimulus is large enough
When the interval between the stimuli decreases, ______
a second action potential is generated until the interval reaches the absolute refractory period
When the stimulus voltage is increased, _______.
a greater-than-threshold depolarization results and sodium permeability into the cell increases to overcome the potassium exiting.
An action potential requires _______.
voltage-gated sodium channels to open and sodium to flow with its electrochemical gradient
To reach threshold, the amount of sodium _______.
entering the cell must overcome the potassium exiting
Which of the following blocks voltage-gated sodium channels?
tetrodotoxin and lidocaine
Which of the following is used to block pain?
lidocaine
Which of the following occurred in the presence of tetrodotoxin?
The number of action potentials decreased.
Which of the following occurred in the presence of tetrodotoxin?
An action potential was always seen at R1.
In the presence of lidocaine, the action potential was NOT affected at R1 because _______.
lidocaine was applied downstream of R1
The effects of lidocaine and tetrodotoxin were _______.
similar, but tetrodotoxin had a greater effect
A nerve is _______.
a bundle of axons
The region on the neuron where action potentials are generated is called the ______.
trigger zone
In this simulation, ___________________ will be used to stimulate the axon.
voltage
We describe the regeneration of the action potential down the membrane of the axon of the neuron as _______.
conduction or propagation
The minimum voltage that is required to generate an action potential is called the _______.
threshold voltage
Increasing the voltage resulted in which of the following?
no change to the action potential
An axon that is more negative than the resting membrane potential is said to be _______.
hyperpolarized
If an increase in extracellular potassium hyperpolarizes a neuron, which of the following would be correct?
It would change the membrane potential to a more negative value
The receptor potential is generated at the _______.
receiving region
Sensory transduction is defined as _______.
the conversion of a stimulus to a change in membrane potential
The receptor potential _______.
amplitude can vary with the stimulus intensity, requires the appropriate stimulus and can be graded with a stimulus intensity
Which of the following describes a depolarization?
The membrane becomes less polarized.
Which of the following statements about receptor potentials is FALSE?
The receptor potential is carried by neuroglia
Which of the following is NOT a functional region of a neuron?
medullary region
The conducting region of the neuron is the _______.
axon
The typical concentration of sodium is _______.
lower than potassium intracellularly.
Which of the following describes a change from the resting membrane potential?
a receptor potential, a synaptic potential or an action potential
What effect did increasing the extracellular potassium have on the resting membrane potential?
The resting membrane potential became less negative
What effect did decreasing the extracellular sodium have on the resting membrane potential?
Only a small change occurred, because the resting neuron is not very permeable to sodium
The channels that provide for the movement of potassium in the resting neuron are _______.
leakage
Establishing the resting membrane potential requires energy through the use of the _______.
sodium-potassium pump
Which of the following was able to detect pressure?
the Pacinian corpuscle and the free nerve ending
Which of the following does NOT describe graded potentials?
They are always depolarizing.
Which of the following responded to a chemical stimulus?
olfactory receptor
When the intensity of the appropriate stimulus was increased, the amplitude of the response _______.
increased
Which of the following statements about receptor potentials is FALSE? 1)
A) The receptor proteins respond to stimuli.
B) The receptor potential is carried by neuroglia.
C) Odor molecules can act as stimuli.
D) They can trigger an action potential.
The receptor potential is carried by neuroglia.
Which of the following is NOT a functional region of a neuron? 2)
A) input region B) secretory region
C) receiving region D) conducting region
input region
The conducting region of the neuron is the _______. 3)
A) cell body B) axon C) axon terminal D) dendrite
axon
The typical concentration of sodium is _______. 4)
A) lower than potassium intracellularly B) higher than potassium intracellularly
C) lower than potassium extracellularly D) the same as potassium intracellularly
lower than potassium intracellularly
Which of the following describes a change from the resting membrane potential? 5)
A) a receptor potential
B) an action potential
C) a synaptic potential
D) a receptor potential, a synaptic potential or an action potential
a receptor potential, a synaptic potential or an action potential
What effect did increasing the extracellular potassium have on the resting membrane potential? 6)
A) The resting membrane potential disappeared.
B) The resting membrane potential became more negative.
C) The resting membrane potential did not change.
D) The resting membrane potential became less negative.
The resting membrane potential became less negative.
What effect did decreasing the extracellular sodium have on the resting membrane potential? 7)
A) Only a small change occurred, because the resting neuron is not very permeable to sodium.
B) Only a small change occurred, because the sodium channels were mostly open.
C) The resting membrane potential disappeared.
D) The resting membrane potential became less negative.
Only a small change occurred, because the resting neuron is not very permeable to sodium.
The channels that provide for the movement of potassium in the resting neuron are _______. 8)
A) chemically gated B) leakage and chemically gated
C) leakage D) voltage gated
leakage
Establishing the resting membrane potential requires energy through the use of the _______. 9)
A) potassium-glucose pump B) sodium leakage channels
C) sodium-glucose pump D) sodium potassum pump
sodium potassum pump
The receptor potential is generated at the _______. 10)
A) conducting region B) receiving region
C) secretory region D) output region
receiving region
Sensory transduction is defined as _______. 11)
A) a change in the amplitude of a receptor potential
B) the conversion of a light stimulus into pain
C) the disappearance of the perception of a stimulus
D) the conversion of a stimulus to a change in membrane potential
the conversion of a stimulus to a change in membrane potential
The receptor potential _______. 12)
A) can be graded with stimulus intensity
B) amplitude can vary with the stimulus intensity
C) amplitude can vary with the stimulus intensity, requires the appropriate stimulus and can be
graded with a stimulus intensity
D) requires the appropriate stimulus
amplitude can vary with the stimulus intensity, requires the appropriate stimulus and can be
graded with a stimulus intensity
Which of the following describes a depolarization? 13)
A) The membrane becomes less polarized.
B) The membrane potential becomes more polarized.
C) The membrane, which was formerly not polarized, now is polarized.
D) The membrane potential becomes more negative.
The membrane becomes less polarized.
Which of the following was able to detect pressure? 14)
A) olfactory receptor
B) Pacinian corpuscle
C) free nerve ending
D) the Pacinian corpuscle and the free nerve ending
the Pacinian corpuscle and the free nerve ending
Which of the following does NOT describe graded potentials? 15)
A) They are always depolarizing.
B) They vary with the intensity of the stimulus.
C) They are local changes.
D) They are changes to the membrane potential.
They are always depolarizing
Which of the following responded to a chemical stimulus? 16)
A) Pacinian corpuscle
B) free nerve ending
C) olfactory receptor
D) both the Pacinian corpuscle and the olfactory receptor
olfactory receptor
When the intensity of the appropriate stimulus was increased, the amplitude of the response
_______.
17)
A) did not change B) increased C) decreased D) was zero
increased
A nerve is _______. 18)
A) a cluster of cell bodies B) another term for a neuron
C) a bundle of axons D) another term for nerve fiber
a bundle of axons
The region on the neuron where action potentials are generated is called the ______. 19)
A) dendrite B) depolarization zone
C) trigger zone D) stimulator zone
trigger zone
20) In this simulation, ___________________ will be used to stimulate the axon. 20)
A) voltage B) light C) heat D) chemicals
voltage
We describe the regeneration of the action potential down the membrane of the axon of the neuron
as _______.
21)
A) hyperpolarization B) propagation
C) conduction D) conduction and propagation
conduction and propagation
The minimum voltage that is required to generate an action potential is called the _______. 22)
A) depolarization voltage B) trigger voltage
C) threshold voltage D) propagation voltage
threshold voltag
Increasing the voltage resulted in which of the following? 23)
A) a decrease in the rate of propagation of the action potential
B) an increase in the size of the action potential
C) no change to the action potential
D) an increase in the rate of propagation of the action potential
no change to the action potential
An axon that is more negative than the resting membrane potential is said to be _______. 24)
A) depolarized B) graded C) hyperpolarized D) at threshold
hyperpolarized
If an increase in extracellular potassium would depolarize a neuron, what would be the effect of the
increased potassium?
25)
A) It would decrease the flow of sodium out of the cell.
B) It would increase the flow of sodium out of the cell.
C) It would change the membrane potential to a more negative value.
D) It would change the membrane potential to a less negative value.
It would change the membrane potential to a less negative value.
An action potential requires _______. 26)
A) voltage-gated sodium channels to open
B) sodium to flow with its electrochemical gradient
C) chemically gated sodium channels to open
D) voltage-gated sodium channels to open and sodium to flow with its electrochemical gradient
voltage-gated sodium channels to open and sodium to flow with its electrochemical gradient
To reach threshold, the amount of sodium _______. 27)
A) exiting the cell must overcome the potassium entering
B) exiting the cell must overcome the potassium exiting
C) entering the cell must overcome the potassium exiting
D) entering the cell must overcome the potassium entering
entering the cell must overcome the potassium exiting
Which of the following blocks voltage-gated sodium channels? 28)
A) lidocaine
B) tetrodotoxin
C) pufferfish toxin
D) tetrodotoxin, pufferfish toxin and lidocaine
tetrodotoxin, pufferfish toxin and lidocaine
Which of the following is used to block pain? 29)
A) tetrodotoxin
B) lidocaine
C) pufferfish toxin
D) tetrodotoxin, pufferfish toxin and lidocaine
lidocaine
Which of the following occurred in the presence of tetrodotoxin? 30)
A) The number of action potentials increased.
B) The number of action potentials decreased.
C) The size of the action potential decreased.
D) The size of the action potential increased.
The number of action potentials decreased.
Which of the following occurred in the presence of tetrodotoxin? 31)
A) An action potential was always seen at R2.
B) An action potential was always seen at R1 and R2.
C) An action potential was always seen at R1.
D) All action potentials were missing.
An action potential was always seen at R1.
In the presence of lidocaine, the action potential was NOT affected at R1 because _______. 32)
A) action potential propagation is in one direction
B) lidocaine was applied upstream of R1
C) lidocaine doesn’t have an effect on the generation of action potentials
D) there are no voltage-gated sodium channels to be affected
action potential propagation is in one direction
The effects of lidocaine and tetrodotoxin were _______. 33)
A) identical
B) similar, but tetrodotoxin had a greater effect
C) very different, because lidocaine had no effect
D) similar, but lidocaine had a greater effect
similar, but tetrodotoxin had a greater effect
Which of the following occurs first in the generation of an action potential? 34)
A) Voltage-gated potassium channels open. B) The membrane repolarizes.
C) The membrane depolarizes. D) Voltage-gated sodium channels open
The membrane depolarizes.
Which of the following occurs during depolarization? 35)
A) Voltage-gated potassium channels open.
B) Some voltage-gated sodium channels inactivate.
C) Sodium flows into the cell.
D) Both A and C occur.
E) All of the above occur.
Sodium flows into the cell
Which of the following occurs during repolarization? 36)
A) Voltage-gated potassium channels open, potassium flows into the cell and some
voltage-gated sodium channels inactivate.
B) Voltage-gated potassium channels open.
C) Potassium flows into the cell.
D) Some voltage-gated sodium channels inactivate.
E) Voltage-gated potassium channels open and potassium flows into the cell.
Voltage-gated potassium channels open, potassium flows into the cell and some
voltage-gated sodium channels inactivate.
Which of the following allow the movement of potassium through the neuronal membrane? 37)
A) voltage-gated potassium channels
B) leakage channels
C) chemically gated potassium channels
D) voltage-gated potassium channels and chemically gated potassium channels
E) leakage channels and voltage-gated potassium channels
leakage channels and voltage-gated potassium channels
Why does the threshold increase when the interval between the stimuli decreases? 38)
A) Potassium is flowing into the cell.
B) Some sodium channels have been inactivated and cannot be reopened immediately.
C) Calcium is flowing out the cell.
D) Sodium is flowing out of the cell.
Some sodium channels have been inactivated and cannot be reopened immediately.
39) During the relative refractory period, _______. 39)
A) a second action potential cannot be generated, no matter how strong the stimulus
B) an action potential can be generated if the stimulus is above threshold
C) an action potential can be generated if the stimulus is above threshold; also the flow of
potassium is opposing depolarization
D) the flow of potassium is opposing depolarization
an action potential can be generated if the stimulus is above threshold; also the flow of
potassium is opposing depolarization
When the interval between the stimuli decreases, _______. 40)
A) a second action potential is generated until the interval reaches the absolute refractory period
B) a second action potential is generated as long as the stimulus is above threshold
C) a second action potential is generated until the interval reaches the relative refractory period
D) a second action potential is generated regardless of the stimulus and the interval
a second action potential is generated until the interval reaches the absolute refractory period
When the stimulus voltage is increased, _______. 41)
A) a greater-than-threshold depolarization results
B) a greater-than-threshold depolarization results and sodium permeability into the cell
increases to overcome the potassium exiting
C) sodium permeability into the cell decreases
D) sodium permeability into the cell increases to overcome the potassium exiting
a greater-than-threshold depolarization results and sodium permeability into the cell
increases to overcome the potassium exiting
When the stimulus intensity increases, _______. 42)
A) the number of action potentials increases B) the size of the action potential increases
C) the size of the action potential decreases D) the number of action potentials decreases
the number of action potentials increase
In this activity, which of the following will increase the stimulus intensity? 43)
A) decreasing the absolute refractory period B) increasing the relative refractory period
C) increasing the absolute refractory period D) increasing the duration of the stimulus
increasing the duration of the stimulus
At threshold, an axon will _______. 44)
A) generate an action potential during the relative refractory period
B) always generate an action potential
C) generate an action potential after the absolute and relative refractory periods have elapsed
D) generate an action potential during the absolute refractory period
generate an action potential after the absolute and relative refractory periods have elapsed
Longer stimuli will allow for _______. 45)
A) the absolute refractory period to finish
B) more action potentials to occur
C) the relative refractory period to finish
D) more action potentials to occur, the absolute refractory period to finish
and the relative refractory period to finish
more action potentials to occur, the absolute refractory period to finish
and the relative refractory period to finish
The time interval between action potentials is called the _______. 46)
A) potential frequency B) interspike interval
C) threshold frequency D) threshold interval
interspike interval
Increase in stimulus intensity _______. 47)
A) increases the size of the action potential
B) has no effect on action potentials
C) increases the frequency of action potentials
D) increases the duration of the action potential
increases the frequency of action potentials
The frequency of action potentials is _______. 48)
A) the reciprocal of the interspike interval
B) measured in hertz
C) measured in hertz and the same as the relative refractory period
D) the reciprocal of the interspike interval and measured in hertz
E) the same as the relative refractory period
the reciprocal of the interspike interval and measured in hertz
During the relative refractory period, _______. 49)
A) adaptation occurs
B) no action potentials are generated
C) the stimulus must be above threshold to generate an action potential
D) the stimulus must be below threshold to generate an action potential
the stimulus must be above threshold to generate an action potential
Which of the following is described correctly? 50)
A) Oligodendrocytes provide the myelination in the peripheral nervous system.
B) Schwann cells provide the myelination in the central nervous system.
C) Schwann cells provide the myelination in the peripheral nervous system.
D) Astrocytes provide the myelination in the central nervous system.
schwann cells provide the myelination in the peripheral nervous system.
The rate with which an action potential travels along an axon _______. 51)
A) is called the conduction velocity
B) is measured in volts/sec
C) is measured in meters/sec
D) is called the conduction velocity and is measured in volts/sec
E) is called the conduction velocity and is measured in meters/sec
is called the conduction velocity and is measured in meters/sec
Which of the following describes a B fiber? 52)
A) large diameter, lightly myelinated B) small diameter, unmyelinated
C) medium diameter, lightly myelinated D) small diameter, lightly myelinated
medium diameter, lightly myelinated
The nodes of Ranvier are _______. 53)
A) locations on the axon where the myelin sheath is very heavy
B) locations on the axon where the myelin sheath is absent
C) a type of glial cell
D) trigger zones of an axon
locations on the axon where the myelin sheath is absen
Which fibers generate the smallest value for conduction velocity? 54)
A) B fibers B) D fibers C) C fibers D) A fibers
C fiber
The time interval for conduction would be shortest with 55)
A) the smallest unmyelinated axons
B) the smallest and most heavily myelinated axons
C) the largest unmyelinated axons
D) the largest and most heavily myelinated axons
the largest and most heavily myelinated axons
Increasing the amount of myelination _______. 56)
A) has no effect on the time between action potentials
B) increases the time between action potentials
C) increases the time between action potentials only for small-diameter axons
D) decreases the time between action potentials
decreases the time between action potentials
In this activity, the stimulus voltage used was _______. 57)
A) suprathreshold for all of the axons
B) altered to accommodate the structural differences
C) the same for all of the axons
D) the same for all of the axons and suprathreshold for all of the axons
the same for all of the axons and suprathreshold for all of the axons
A synaptic cleft can be found between _______. 58)
A) a neuron and a muscle
B) a neuron and a gland
C) a neuron and another neuron
D) a neuron and another neuron, a neuron and a muscle, as well as a neuron and a gland
a neuron and another neuron, a neuron and a muscle, as well as a neuron and a gland
The membrane potential that occurs when neurotransmitters bind to their receptors is called
_______.
59)
A) a postsynaptic potential
B) an action potential
C) an action potential and a receptor potential
D) a receptor potential
a postsynaptic potential
The release of neurotransmitter occurs _______. 60)
A) at the motor end plate B) all along the axon
C) at the axon terminal D) from the dendrites
at the axon terminal
Which of the following occurs first? 61)
A) An action potential arrives at the axon terminal.
B) Extracellular calcium enters the axon terminal.
C) Synaptic vesicles exit by exocytosis.
D) Voltage-gated calcium channels are opened
An action potential arrives at the axon terminal.
At a chemical synapse, the intensity of the stimulus is coded for by _______. 62)
A) the size of the action potential and the amount of neurotransmitter released
B) the amount of neurotransmitter released and the amount of calcium that enters the axon
terminal
C) the amount of calcium that enters the axon terminal
D) the size of the action potential
E) the amount of neurotransmitter released
the amount of neurotransmitter released and the amount of calcium that enters the axon
terminal
When the calcium was removed from the extracellular solution, _______. 63)
A) no neurotransmitter was released
B) the amount of neurotransmitter released decreased
C) the amount of neurotransmitter released increased
D) the amount of neurotransmitter released did not change
no neurotransmitter was released
When magnesium was added to the extracellular solution, _______. 64)
A) no neurotransmitter was released
B) the amount of neurotransmitter released increased
C) the amount of neurotransmitter released decreased
D) the amount of neurotransmitter released did not change
the amount of neurotransmitter released decreased
Calcium and magnesium are both _______. 65)
A) monovalent cations B) divalent anions
C) divalent cations D) monovalent anions
divalent cations
A single action potential is described as _______. 66)
A) graded by the functional area involved B) not graded
C) graded by the frequency of the stimulus D) graded by the intensity of the stimulus
not graded
A suprathreshold stimulus results in _______. 67)
A) more action potentials B) fewer action potentials
C) the disappearance of action potentials D) larger action potentials
more action potentials
A depolarizing synaptic potential is also known as _______. 68)
A) a hyperpolarizing postsynaptic potential B) an inhibitory postsynaptic potential
C) an excitatory presynaptic potential D) an excitatory postsynaptic potential
an excitatory postsynaptic potential
The stimulus for graded potentials includes _______. 69)
A) sensory stimuli and neurotransmitter B) sensory stimuli
C) neurotransmitter D) voltage
sensory stimuli and neurotransmitter
A weak, subthreshold stimulus will result in _______. 70)
A) a small depolarization at the receiving end of the interneuron
B) an action potential at the receiving end of the neuron
C) release of neurotransmitter at the axon terminal of the sensory neuron
D) a small depolarization at the receiving end of the neuron
a small depolarization at the receiving end of the neuron
Which stimulus was at or above threshold? 71)
A) strong B) weak
C) moderate D) the moderate and strong stimuli
the moderate and strong stimuli
Increasing the strength of the stimulus applied to the sensory receptor increased _______. 72)
A) the amount of neurotransmitter released at the axon terminal of the sensory neuron
B) the frequency of action potentials in the sensory neuron
C) the frequency of action potentials in the interneuron
D) the frequency of action potentials in the sensory neuron and the amount of neurotransmitter
released at the axon terminal of the sensory neuron
E) the frequency of action potentials in the sensory neuron, the amount of neurotransmitter
released at the axon terminal of the sensory neuron and the frequency of action potentials in
the interneuron
the frequency of action potentials in the sensory neuron, the amount of neurotransmitter
released at the axon terminal of the sensory neuron and the frequency of action potentials in
the interneuron
An excitatory postsynaptic potential occurs _______. 73)
A) at the axon terminal of the interneuron
B) at the receiving end of the sensory neuron
C) at the receiving end of the interneuron
D) at the axon terminal of the sensory neuron
at the receiving end of the interneuron

Neurophysiology

Which of the following statements about receptor potentials is FALSE?

-Odor molecules can act as stimuli.
-The receptor potential is carried by neuroglia.
-The receptor proteins respond to stimuli.
-They can trigger an action potential.

The receptor potential is carried by neuroglia.

Which of the following is NOT a functional region of a neuron?

secretory region
conducting region
receiving region
medullary region

medullary region

The conducting region of the neuron is the _______.

cell body
axon
axon terminal
dendrite

axon

The typical concentration of sodium is _______.

– the same as potassium intracellularly.
– lower than potassium extracellularly.
– lower than potassium intracellularly.
– higher than potassium intracellularly.

– lower than potassium intracellularly.

Which of the following describes a change from the resting membrane potential?

– an action potential
– a synaptic potential
– a receptor potential
– a receptor potential, a synaptic potential or an action potential

a receptor potential, a synaptic potential or an action potential

What effect did increasing the extracellular potassium have on the resting membrane potential?

– The resting membrane potential became less negative.
– The resting membrane potential became more negative.
– The resting membrane potential did not change.
– The resting membrane potential disappeared.

The resting membrane potential became less negative.

What effect did decreasing the extracellular sodium have on the resting membrane potential?

– Only a small change occurred, because the sodium channels were mostly open.
– The resting membrane potential disappeared.
– Only a small change occurred, because the resting neuron is not very permeable to sodium.
– The resting membrane potential became less negative.

Only a small change occurred, because the resting neuron is not very permeable to sodium.

The channels that provide for the movement of potassium in the resting neuron are _______.

– leakage and chemically gated.
– chemically gated
– voltage gated
– leakage

leakage

Establishing the resting membrane potential requires energy through the use of the _______.

– sodium-glucose pump
– potassium-glucose pump
– sodium-potassium pump
– sodium leakage channels

sodium-potassium pump

The receptor potential is generated at the _______.

receiving region
conducting region
output region
secretory region

receiving region

Sensory transduction is defined as _______.

– the conversion of a stimulus to a change in membrane potential
– the disappearance of the perception of a stimulus
– the conversion of a light stimulus into pain
– a change in the amplitude of a receptor potential

– the conversion of a stimulus to a change in membrane potential

The receptor potential _______.

– can be graded with stimulus intensity
– amplitude can vary with the stimulus intensity, requires the appropriate stimulus and can be graded with a stimulus intensity
– amplitude can vary with the stimulus intensity
– requires the appropriate stimulus

amplitude can vary with the stimulus intensity, requires the appropriate stimulus and can be graded with a stimulus intensity

Which of the following describes a depolarization?

– The membrane potential becomes more polarized.
– The membrane potential becomes more negative.
– The membrane becomes less polarized.
– The membrane, which was formerly not polarized, now is polarized.

The membrane becomes less polarized.

Which of the following was able to detect pressure?

– the Pacinian corpuscle and the free nerve ending
– free nerve ending
– olfactory receptor
– Pacinian corpuscle

the Pacinian corpuscle and the free nerve ending

Which of the following does NOT describe graded potentials?

– They vary with the intensity of the stimulus.
– They are changes to the membrane potential.
– They are always depolarizing.
– They are local changes.

They are always depolarizing.

Which of the following responded to a chemical stimulus?

– Pacinian corpuscle
– free nerve ending
– olfactory receptor
– both the Pacinian corpuscle and the olfactory receptor

olfactory receptor

When the intensity of the appropriate stimulus was increased, the amplitude of the response _______.

was zero
did not change
decreased
increased

increased

A nerve is _______.

another term for a neuron
a cluster of cell bodies
a bundle of axons
another term for nerve fiber

a bundle of axons

The region on the neuron where action potentials are generated is called the ______.

trigger zone
depolarization zone
stimulator zone
dendrite

trigger zone

In this simulation, ___________________ will be used to stimulate the axon.

light
heat
voltage
chemicals

voltage

We describe the regeneration of the action potential down the membrane of the axon of the neuron as _______.

hyperpolarization
conduction or propagation
conduction
propagation

conduction or propagation

The minimum voltage that is required to generate an action potential is called the _______.

depolarization voltage
propagation voltage
threshold voltage
trigger voltage

threshold voltage

Increasing the voltage resulted in which of the following?

– an increase in the rate of propagation of the action potential
– an increase in the size of the action potential
– a decrease in the rate of propagation of the action potential
– no change to the action potential

no change to the action potential

An axon that is more negative than the resting membrane potential is said to be _______.

depolarized
hyperpolarized
at threshold
graded

hyperpolarized

If an increase in extracellular potassium hyperpolarizes a neuron, which of the following would be correct?

-It would change the membrane potential to a more negative value.
-It would decrease the flow of sodium out of the cell.
-It would change the membrane potential to a less negative value.
-It would increase the flow of sodium out of the cell.

-It would change the membrane potential to a more negative value.

An action potential requires _______.

– voltage-gated sodium channels to open
– sodium to flow with its electrochemical gradient
– chemically gated sodium channels to open
– voltage-gated sodium channels to open and sodium to flow with its electrochemical gradient

voltage-gated sodium channels to open and sodium to flow with its electrochemical gradient

To reach threshold, the amount of sodium _______.

– entering the cell must overcome the potassium exiting
– exiting the cell must overcome the potassium exiting
– entering the cell must overcome the potassium entering
– exiting the cell must overcome the potassium entering

entering the cell must overcome the potassium exiting

Which of the following blocks voltage-gated sodium channels?

lidocaine
tetrodotoxin
tetrodotoxin and lidocaine
potassium

tetrodotoxin and lidocaine

Which of the following is used to block pain?

tetrodotoxin
tetrodotoxin and lidocaine
lidocaine
potassium

lidocaine

Which of the following occurred in the presence of tetrodotoxin?

The size of the action potential decreased.
The number of action potentials increased.
The number of action potentials decreased.
The size of the action potential increased.

The number of action potentials decreased.

Which of the following occurred in the presence of tetrodotoxin?

An action potential was always seen at R1.
All action potentials were missing.
An action potential was always seen at R1 and R2.
An action potential was always seen at R2.

An action potential was always seen at R1.

In the presence of lidocaine, the action potential was NOT affected at R1 because _______.

– lidocaine was applied downstream of R1
– there are no voltage-gated sodium channels to be affected
– lidocaine doesn’t have an effect on the generation of action potentials
– lidocaine was applied upstream of R1

lidocaine was applied downstream of R1

The effects of lidocaine and tetrodotoxin were _______.

– identical
– similar, but lidocaine had a greater effect
– similar, but tetrodotoxin had a greater effect
– very different, because lidocaine had no effect

similar, but tetrodotoxin had a greater effect

Which of the following occurs first in the generation of an action potential?

Voltage-gated sodium channels open.
Voltage-gated potassium channels open.
The membrane depolarizes.
The membrane repolarizes.

The membrane depolarizes.

Which of the following occurs during depolarization?

Both A and C occur.
Voltage-gated sodium channels close.
Voltage-gated potassium channels close.
Sodium flows into the cell.
All of the above occur.

Sodium flows into the cell.

Which of the following occurs during repolarization?

– Voltage-gated sodium channels open. Sodium flows into the cell.
– Voltage-gated potassium channels remain open and some voltage-gated sodium channels inactivate. Potassium flows into the cell.
– Voltage-gated sodium channels open and some voltage-gated potassium channels inactivate. Sodium flows out of the cell.
– Voltage-gated potassium channels open and some voltage-gated sodium channels inactivate. Potassium flows out of the cell.
– Voltage-gated potassium channels open and potassium flows into the cell.

Voltage-gated potassium channels open and some voltage-gated sodium channels inactivate. Potassium flows out of the cell.

Which of the following allow the movement of potassium through the neuronal membrane?

simple diffusion
leakage channels
leakage channels and voltage-gated potassium channels
voltage-gated potassium channels

leakage channels and voltage-gated potassium channels

Why does the threshold increase when the interval between the stimuli decreases?

– Potassium is flowing into the cell.
– Calcium is flowing out the cell.
– Sodium is flowing out of the cell.
– Some sodium channels have been inactivated and cannot be reopened immediately.

Some sodium channels have been inactivated and cannot be reopened immediately

During the relative refractory period, _______.

– a second action potential cannot be generated, no matter how strong the stimulus.
– the flow of potassium is also depolarizing the neuron.
– another action potential can be generated provided the stimulus is large enough.
– another action potential can be generated provided the stimulus is relatively smaller than the original stimulus.

another action potential can be generated provided the stimulus is large enough

When the interval between the stimuli decreases, _______.

– a second action potential is generated as long as the stimulus is above threshold
– a second action potential is generated until the interval reaches the relative refractory period
– a second action potential is generated until the interval reaches the absolute refractory period
– a second action potential is generated regardless of the stimulus and the interval

a second action potential is generated until the interval reaches the absolute refractory period

When the stimulus voltage is increased, _______.

– sodium permeability into the cell increases to overcome the potassium exiting
– a greater-than-threshold depolarization results and sodium permeability into the cell increases to overcome the potassium exiting.
– a greater-than-threshold depolarization results
– sodium permeability into the cell decreases

a greater-than-threshold depolarization results and sodium permeability into the cell increases to overcome the potassium exiting

When the stimulus intensity increases, _______.

– the number of action potentials decreases
– the size of the action potential decreases
– the size of the action potential increases
– the number of action potentials increases

the number of action potentials increases

In this activity, which of the following will increase the stimulus intensity?

– increasing the absolute refractory period
– decreasing the absolute refractory period
– increasing the duration of the stimulus
– increasing the relative refractory period

increasing the duration of the stimulus

At threshold, axons will _______.

– Usually be at the end of their absolute refractory period.
– Begin to hyperpolarize the membrane potential.
– Likely generate an action potential if refractory periods have elapsed.
– Always generate an action potential.

Likely generate an action potential if refractory periods have elapsed.

Longer stimuli will allow for _______.

-the absolute refractory period to finish
– more action potentials to occur, the absolute refractory period to finish and the relative refractory period to finish
– the relative refractory period to finish
– more action potentials to occur

more action potentials to occur, the absolute refractory period to finish and the relative refractory period to finish

The time interval between action potentials is called the _______.

potential frequency
threshold interval
interspike interval
threshold frequency

interspike interval

Increase in stimulus intensity _______.

– increases the duration of the action potential
– increases the frequency of action potentials
– has no effect on action potentials
– increases the size of the action potential

increases the frequency of action potentials

The frequency of action potentials is _______.

– measured in hertz, and the same as the relative refractory period
– the reciprocal of the interspike interval, and measured in hertz
– the same as the relative refractory period
– the reciprocal of the interspike interval
– measured in hertz

– the reciprocal of the interspike interval, and measured in hertz

During the relative refractory period, _______.

– adaptation occurs
– the stimulus must be above threshold to generate an action potential
– the stimulus must be below threshold to generate an action potential
– no action potentials are generated

the stimulus must be above threshold to generate an action potential

Which of the following is described correctly?

– Schwann cells provide the myelination in the peripheral nervous system.
– Astrocytes provide the myelination in the central nervous system.
– Oligodendrocytes provide the myelination in the peripheral nervous system.
– Schwann cells provide the myelination in the central nervous system.

Schwann cells provide the myelination in the peripheral nervous system.

The rate with which an action potential travels along an axon _______.

– is measured in meters/sec
– is called the conduction velocity
– is called the conduction velocity and is measured in volts/sec
– is measured in volts/sec
– is called the conduction velocity and is measured in meters/sec

is called the conduction velocity and is measured in meters/sec

Which of the following describes a B fiber?

– small diameter, unmyelinated
– large diameter, lightly myelinated
– medium diameter, lightly myelinated
– small diameter, lightly myelinated

medium diameter, lightly myelinated

The nodes of Ranvier are _______.

– locations on the axon where the myelin sheath is very heavy
– trigger zones of an axon
– a type of glial cell
– locations on the axon where the myelin sheath is absent

locations on the axon where the myelin sheath is absent

Which fibers generate the smallest value for conduction velocity?

A fibers
B fibers
D fibers
C fibers

C fibers

The time interval for conduction would be shortest with

– the largest unmyelinated axons
– the smallest and most heavily myelinated axons
– the largest and most heavily myelinated axons
– the smallest unmyelinated axons

the largest and most heavily myelinated axons

Increasing the amount of myelination _______.

– increases the time between action potentials
– increases the time between action potentials only for small-diameter axons
– decreases the time between action potentials
– has no effect on the time between action potentials

decreases the time between action potentials

In this activity, the stimulus voltage used was _______.

– altered to accommodate the structural differences
– the same for all of the axons
– suprathreshold for all of the axons
– the same for all of the axons and suprathreshold for all of the axons

the same for all of the axons and suprathreshold for all of the axons

 

Blood Analysis

Oxygen is attached to
an iron atom located on the heme portion of hemoglobin
The oxygen-carrying capacity of the blood is evaluated using
hematocrit and hemoglobin measurements
Release of which of the following hormones results in higher levels of erythrocytes?
testosterone and erythropoietin
Which type of anemia is a genetic disorder resulting in abnormally shaped erythrocytes?
sickle cell anemia
The blood sample from which of the following had the highest hematocrit?
a healthy male living in Denver
The blood sample(s) from which of the following displayed polycythemia?
a healthy female living in Denver
a healthy male living in Denver
The hematocrit for the female with iron-deficiency anemia was
below normal
Which of the samples are from patients that suffer from a condition in which insufficient oxygen is transported to the body’s cells?
samples 5 and 6
Which of the following would indicate a worsening of the disease?
increased ESR with rheumatoid arthritis
Rouleaux formation is characterized by
an increase in ESR
ESR is useful in distinguishing between
angina and a myocardial infarction as well as acute appendicitis and ruptured ectopic pregnancy
Erythrocyte sedimentation relies upon
gravity
Which of the following had the fastest sedimentation rate?
the individual suffering a myocardial infarction
Which sample did NOT settle at all in one hour?
the individual with sickle cell anemia
In comparing the sedimentation rate for the individual with angina pectoris with that of the healthy individual, which of the following statements is true?
The sedimentation rates were the same for both individuals.
Which of the following explains the result for the individual with sickle cell anemia?
The shape of the red blood cells prevented them from settling.
Each hemoglobin molecule can carry ______________ oxygen molecule(s).
4
Which of the following does NOT result in an increase in hemoglobin levels?
hyperthyroidism
Oxyhemoglobin
has oxygen attached to the iron atom
Recall that the normal range for the hematocrit for a female is 37 – 47%, and the normal range for the hemoglobin level for a female is 12 – 16 g/100 ml. Describe hemoglobin and hematocrit values for the female with iron-deficiency anemia.
The hemoglobin was below normal, and the hematocrit was normal.
Which of the following blood samples did NOT have a normal ratio of PCV to Hb?
the female with iron-deficiency anemia
Which of the following individuals had the highest hemoglobin level?
the female Olympic athlete
Which of the following describes the blood sample for the female Olympic athlete?
Her hemoglobin level and her hematocrit were above normal.
A person with type O blood has
neither A nor B agglutinogens
With respect to ABO and Rh blood groups, there are __________ different blood types.
8
A person with type AB blood has
A and B antigens and neither anti-A nor anti-B antibodies.
A person with A+ blood has
the A antigen on the surface of the red blood cells
Rh antigen on the surface of the red blood cells
anti-B antibodies
Which blood sample contained the universal recipient?
AB
Which of the following terms can be used interchangeably?
antigen and agglutinogen
Blood type A- would give which of the following results?
agglutination with anti-A antibodies
Which of the blood samples tested could donate to a person with type A+ blood?
A+
O+
LDLs contain
cholesterol and protein
Hypocholesterolemia is linked to
low levels of serotonin
The cholesterol determination is
enzymatic and colorimetric
Which of the following were disposed of in the biohazardous waste disposal?
the alcohol wipe, the lancet, and the cholesterol strip

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