EX3

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