chapter 4 - How Do Neurons Use Electrical Signals to Transmit Information? Flashcards Preview

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Flashcards in chapter 4 - How Do Neurons Use Electrical Signals to Transmit Information? Deck (84):
1

Approximately ______ people have a seizure at some point in their lifetime.
A) 1 in 5
B) 1 in 20
C) 1 in 100
D) 1 in 1000

B) 1 in 20

2

Erica is an 18-year-old and in her first year of university. One day while she was watching a video in class, Erica started to hear what she thought was music playing. Suddenly she began shaking in her seat and fell to the floor. After the incident ended, one of her classmates helped her to the campus medical center, where she was later diagnosed as having:
A) Huntington’s disease.
B) Parkinson’s disease.
C) epilepsy.
D) myasthenia gravis.

C) epilepsy.

3

3. The three symptoms that are common to many forms of epilepsy are:
A) abnormal vocalizations, an aura, and loss of consciousness.
B) headache, abnormal movements, and loss of consciousness.
C) an aura, abnormal movements, and loss of consciousness.
D) abnormal vocalizations, hallucinations, and an aura.

C) an aura, abnormal movements, and loss of consciousness.

4

René Descartes believed that ______ carried signals through the nervous system.
A) neurons
B) phlegm
C) the pineal gland
D) cerebrospinal fluid

D) cerebrospinal fluid

5

The technique of electrical stimulation was first discovered by:
A) Luigi Galvani.
B) René Descartes.
C) Gustave Fritsch and Edward Hitzig.
D) David Ferrier.

A) Luigi Galvani.

6

Electricity is a flow of electrons from a body that contains a higher charge (more electrons) to a body that has a lower charge (fewer electrons). The body containing the higher electrical charge is called a:
A) positive pole.
B) negative pole.
C) dipole.
D) ground pole

B) negative pole.

7

Another term for volts is:
A) electrical potential between two poles.
B) current flow.
C) amps.
D) current flow and amps.

A) electrical potential between two poles.

8

In a now-famous experiment Fritsch and Hitzig discovered that electrical stimulation of the neocortex led to:
A) hearing sounds.
B) movements.
C) seizures.
D) seeing patterns.

B) movements.

9

Roberts Bartholow is remembered for being the first person to stimulate the brain(s) of a:
A) dog.
B) rabbit.
C) human.
D) a dog and a rabbit.

C) human.

10

When Richard Caton first measured fluctuations on a voltmeter from electrodes placed on the scalp of a human subject, he was recording what we now call:
A) the electroencephalogram.
B) the action potential.
C) the magnetoencephalogram.
D) axonal conductance.

A) the electroencephalogram.

11

An electroencephalogram, or EEG, can theoretically be recorded by:
A) a voltmeter.
B) a current meter.
C) an amp meter.
D) both a voltmeter and a current meter.

A) a voltmeter

12

12. Measuring the speed of information flow in a nerve was first performed by:
A) Hermann von Helmholtz.
B) Wilder Penfield.
C) Eduard Hitzig.
D) Gustave Fritsch

A) Hermann von Helmholtz

13

Neurons in most animals, including humans, are approximately:
A) 1 to 20 thousandths of a millimeter in diameter.
B) 50 to 100 thousandths of a millimeter in diameter.
C) 500 to 700 thousandths of a millimeter in diameter.
D) up to a millimeter in diameter

A) 1 to 20 thousandths of a millimeter in diameter

14

Because the giant axons of the squid are nearly ______ in diameter, they were used to record electrical activity in neurons for the first time.
A) 1 centimeter
B) 1 millimeter
C) 5 millimeters
D) 0.1 millimeter

B) 1 millimeter

15

Microelectrodes can:
A) be made from glass.
B) be made from wire.
C) have a tip as small as 0.001 millimeter.
D) All of the answers are correct.

D) All of the answers are correct

16

The ability to record from single neurons was made possible by the invention of:
A) the electroencephalogram.
B) the oscilloscope.
C) the microelectrode.
D) both the oscilloscope and the microelectrode.

D) both the oscilloscope and the microelectrode

17

The patch technique involves:
A) placing the tip of a microelectrode on an axon.
B) recording between two microelectrodes, one inside the axon and the other outside.
C) placing the tip of the microelectrode in an axon and applying some back suction.
D) placing the tips of the two microelectrodes in an axon and recording between them.

C) placing the tip of the microelectrode in an axon and applying some back suction

18

In order to measure the voltage across the cell membrane you would normally:
A) insert two electrodes into the axon and measure the voltage difference.
B) place one electrode on the outer surface of an axon’s membrane and another inside the axon
and measure the voltage difference.
C) place two electrodes on the outer surface of the axon’s membrane and measure the voltage
difference.
D) All of the answers are correct.

B) place one electrode on the outer surface of an axon’s membrane and another inside the axon
and measure the voltage difference

19

When a substance moves from an area of high concentration to an area of low concentration, it is
an example of a(n):
A) concentration gradient.
B) voltage gradient.
C) ionic translocation.
D) None of the answers is correct.

A) concentration gradient

20

The movement of ions from an area of high concentration to an area of low concentration is called:
A) a concentration gradient.
B) a voltage gradient.
C) diffusion.
D) ionic translocation.

C) diffusion

21

The notion that opposites attract is an analogy that best describes:
A) a concentration gradient.
B) a voltage gradient.
C) diffusion.
D) All of the answers are correct.

B) a voltage gradient

22

If a small amount of dye is placed in a beaker of water, it will flow away from the initial point of contact. The ensuing process illustrates:
A) diffusion.
B) concentration.
C) charge.
D) electrostatic pressure

A) diffusion

23

Channels in the cell membrane are formed by:
A) sodium ions.
B) potassium ions.
C) protein molecules.
D) lipids.

C) protein molecules

24

Which of the following is not involved in producing the resting potential?
A) potassium ions
B) chloride ions
C) calcium ions
D) sodium ions

C) calcium ions

25

The resting potential:
A) is –70 mV in all species.
B) can vary from –40 mV to –90 mV within a species.
C) can vary from –40 mV to –90 mV between species.
D) None of the answers is correct.

C) can vary from –40 mV to –90 mV between species

26

A change in the resting potential from –70 mV to –73 mV is called:
A) depolarization.
B) hyperpolarization.
C) graded excitatory potential.
D) nothing, as these changes occur spontaneously.

B) hyperpolarization

27

When the neuron is at rest, ______ channels are normally closed, whereas ______ is free to enter and leave the cell.
A) K+; Na+
B) Cl–; Na+
C) Na+; K+
D) K+; Cl–

C) Na+; K+

28

Which of the following is not true?
A) The cell membrane is semipermeable, so it keeps in large negatively charged protein
molecules.
B) The membrane keeps out Na+ and allows K+ and C1– to pass more freely.
C) The membrane has a sodium–potassium pump that removes potassium from inside the cell
and replaces it with sodium.
D) The summed charges of the unequally distributed ions leave the inside of the membrane at
–70 mV relative to the outside. This is the cell’s resting potential.

C) The membrane has a sodium–potassium pump that removes potassium from inside the cell
and replaces it with sodium

29

Large protein anions are:
A) manufactured by glial cells.
B) manufactured within a neuron.
C) transported to a neuron by glial cells.
D) not part of a neuron.

B) manufactured within a neuron

30

There are approximately ______ K+ ions inside the cell membrane compared to outside the cell.
A) 20 times more
B) 2 times more
C) one-tenth as many
D) equal concentrations of

A) 20 times more

31

The negative charge inside of the cell membrane is largely a product of the presence of:
A) negatively charged potassium ions.
B) negatively charged sodium ions.
C) negatively charged protein anions.
D) All of the answers are correct.

C) negatively charged protein anions

32

Small voltage fluctuations in the cell membrane that occur near the vicinity of the axon are called:
A) action potentials.
B) graded potentials.
C) ion fluctuations.
D) nerve impulses.

B) graded potentials

33

The sodium–potassium pump:
A) continuously exchanges three intracellular Na+ for two extracellular K+.
B) continuously exchanges three intracellular K+ for two extracellular Na+.
C) continuously exchanges three extracellular Na+ for two intracellular K+.
D) intermittently exchanges three intracellular K+ for two extracellular Na+.

A) continuously exchanges three intracellular Na+ for two extracellular K+

34

A change in the resting potential from –70 mV to –65 mV is called:
A) an excitatory postsynaptic potential.
B) repolarization.
C) depolarization.
D) hyperpolarization

C) depolarization

35

The use of tetrodotoxin (puffer fish poison) surrounding an axon demonstrates:
A) the role of potassium channels in hyperpolarization.
B) the role of sodium channels in depolarization.
C) the role of potassium channels in depolarization.
D) the role of sodium channels in hyperpolarization.

B) the role of sodium channels in depolarization.

36

Tetraethylammonium (TEA):
A) blocks potassium channels.
B) blocks sodium channels.
C) blocks chlorine channels.
D) neutralizes large protein molecules.

A) blocks potassium channels

37

You and a friend are visiting Japan and are eating at an authentic sushi restaurant. The sushi chef brings you some samples of puffer fish and within a few minutes both of you and your friend begin feeling extremely weak, to the point where your muscles will not contract and you are no longer able to think clearly. You ask the sushi chef to call an ambulance because:
A) you have an acute case of food poisoning.
B) you may have ingested tetrodotoxin, which is a sodium channel blocker.
C) you may have ingested tetrodotoxin, which prevents potassium channels from closing.
D) you may have ingested TEA, which blocks potassium channels and prevents
hyperpolarization.

B) you may have ingested tetrodotoxin, which is a sodium channel blocker

38

An action potential is:
A) a large graded potential.
B) a large, brief reversal in the polarity of a membrane.
C) the same as a threshold potential.
D) seldom shorter than 10 milliseconds.

B) a large, brief reversal in the polarity of a membrane

39

The voltage of a neural membrane that is sufficient to cause an action potential is approximately ______ and is referred to as a(n) ______.
A) –70 mV; resting potential_
B) –50 mV; graded potential
C) –65 mV; threshold potential
D) –50 mV; threshold potential

D) –50 mV; threshold potential

40

During an action potential:
A) the voltage of the cell membrane drops to 0 and then returns to –70 mV.
B) the voltage of the cell membrane drops to 0, returns to about –100 mV, and then goes to 70
mV.
C) the voltage of the cell membrane goes to about +30 mV and then drops to –70 mV.
D) the voltage of the cell membrane goes to about +30 mV, drops to –100 mV, and then goes to
–70 mV.

C) the voltage of the cell membrane goes to about +30 mV and then drops to –70 mV

41

The action potential normally consists of the summed current changes caused by the ______ and
the ______.
A) inflow of sodium; outflow of potassium
B) outflow of sodium; inflow of potassium
C) inflow of calcium; outflow of potassium
D) inflow of sodium; outflow of chloride

A) inflow of sodium; outflow of potassium

42

Na+ and K+ channels on axons are mainly:
A) neurotransmitter dependent.
B) voltage dependent.
C) calcium dependent.
D) both neurotransmitter and voltage dependent.

B) voltage dependent

43

______ channels are more sensitive than ______ channels, so they open first during the action potential.
A) Calcium; potassium
B) Potassium; calcium
C) Sodium; potassium
D) All channels are equally sensitive.

C) Sodium; potassium

44

Sodium channels close when the membrane potential reaches approximately:
A) +50 mV
B) +30 mV
C) –50 mV
D) 0mV

B) +30 mV

45

Voltage-sensitive sodium channels are active:
A) whenever the cell membrane starts to depolarize.
B) when the voltage across the membrane reaches 0.
C) when the threshold voltage of the cell is reached.
D) when the voltage across the membrane reaches +30 mV.

C) when the threshold voltage of the cell is reached

46

A cell cannot produce an action potential:
A) during the relative refractory period.
B) during the absolute refractory period.
C) during the intermediate refractory period.
D) None of the answers is correct.

B) during the absolute refractory period

47

During the ______ it is more difficult, but not impossible, for another action potential to be initiated.
A) absolute refractory period
B) rebound period
C) relative refractory period
D) action potential

C) relative refractory period

48

Refractory periods are due to:
A) voltage-sensitive sodium and potassium channels.
B) voltage-sensitive chloride channels.
C) the time constraint on the sodium–potassium pump.
D) inhibitory postsynaptic potentials.

A) voltage-sensitive sodium and potassium channels

49

The repolarization of the neuronal membrane is largely due to the:
A) closing of calcium channels, stopping the influx of calcium.
B) opening of potassium channels, allowing the outflow of potassium.
C) closing of potassium channels, stopping the influx of potassium.
D) closing of sodium channels, stopping the outflow of sodium.

B) opening of potassium channels, allowing the outflow of potassium

50

Nerve impulse describes:
A) an action potential crossing the synaptic cleft.
B) input at the dendrites of a cell.
C) the movement of an action potential along the axon.
D) an action potential along the combined axons, which are called nerves.

C) the movement of an action potential along the axon

51

The propagation of the nerve impulse is:
A) not decremental.
B) related to the opening of potassium and sodium ion channels.
C) similar to the effect of falling dominoes.
D) All of the answers are correct.

D) All of the answers are correct

52

Because of refractory periods, the maximum firing rate of a neuron is approximately:
A) 500 impulses per second.
B) 1000 impulses per second.
C) 100 impulses per second.
D) 200 impulses per second.

D) 200 impulses per second

53

An action potential usually goes only in one direction in an axon because:
A) the ions can flow only in one direction.
B) the refractory periods force the impulse to go in one direction.
C) the ion flow is attracted to chemicals in the synaptic knob.
D) autoreceptors inhibit backward flow of ions.

B) the refractory periods force the impulse to go in one direction

54

The speed at which nerve impulses travel down an axon are greatly increased by:
A) myelin.
B) refractory periods.
C) the length of the axon.
D) calcium channels.

A) myelin

55

Saltatory conduction is aided by ______ located at ______.
A) sodium–potassium pumps; terminal buttons
B) sodium and potassium channels; nodes of Ranvier
C) calcium channels; nodes of Ranvier
D) glial cells; nodes of Ranvier

B) sodium and potassium channels; nodes of Ranvier

56

Saltatory conduction refers to:
A) sodium concentration in the extracellular fluid.
B) action potentials that are facilitated by sodium.
C) action potentials jumping from one node to the next.
D) the leakage of the sodium channels that require the existence of a sodium–potassium pump.

C) action potentials jumping from one node to the next

57

On larger myelinated axons, nerve impulses can reach speeds of up to _______ meters per second.
A) 100
B) 50
C) 120
D) 30

C) 120

58

A brief depolarization of the neuronal membrane that makes it more likely that the neuron will fire
an action potential is called:
A) saltatory conduction.
B) an inhibitory postsynaptic potential (IPSP).
C) an excitatory postsynaptic potential (EPSP).
D) spatial summation.

C) an excitatory postsynaptic potential (EPSP)

59

A brief hyperpolarization of the neuronal membrane that makes it less likely that the neuron will fire an action potential is called:
A) saltatory conduction.
B) an inhibitory postsynaptic potential (IPSP).
C) an excitatory postsynaptic potential (EPSP).
D) spatial summation.

B) an inhibitory postsynaptic potential (IPSP)

60

Excitatory postsynaptic potentials (EPSPs) are recorded:
A) at the synaptic knob.
B) in the axon.
C) in the dendrites.
D) in the cell body.

D) in the cell body

61

Myasthenia gravis is:
A) an autoimmune disease.
B) more common in men than women.
C) caused by a viral infection.
D) caused by a bacterial infection.

A) an autoimmune disease

62

______ is often accompanied by drooping eyelids, difficulty swallowing, and general fatigue.
A) Huntington’s disease
B) Tay-Sachs disease
C) Myasthenia gravis
D) Tetrodotoxin poisoning

C) Myasthenia gravis

63

Inhibitory postsynaptic potentials (IPSPs) are associated with:
A) the opening of potassium channels, allowing the outflow of potassium.
B) the opening of sodium channels, allowing the influx of sodium.
C) the closing of potassium channels, stopping the influx of potassium.
D) the closing of sodium channels, stopping the influx of potassium.

A) the opening of potassium channels, allowing the outflow of potassium

64

EPSPs are associated with:
A) the opening of potassium channels, allowing the outflow of potassium.
B) the opening of sodium channels, allowing the influx of sodium.
C) the closing of potassium channels, stopping the influx of potassium.
D) the closing of sodium channels, stopping the influx of potassium.

B) the opening of sodium channels, allowing the influx of sodium

65

In order for an EPSP to cause another action potential, the stimulation must reach the _______, which is(are) rich in voltage-sensitive ion channels.
A) axon hillock
B) cell body
C) dendrites
D) terminal buttons

A) axon hillock

66

Stimulation producing two EPSPs in quick succession illustrates:
A) spatial summation.
B) temporal summation.
C) both spatial and temporal summation.
D) neither spatial nor temporal summation.

B) temporal summation

67

Simultaneous stimulation at two different locations on a cell membrane that lead to an EPSP are an example of:
A) spatial summation.
B) temporal summation.
C) both spatial and temporal summation.
D) neither spatial nor temporal summation.

A) spatial summation

68

Spatial summation is more likely to occur:
A) when the two impulses are far apart on the membrane.
B) when the two impulses are close together on the membrane.
C) without regard to distance on the membrane.
D) when one EPSP follows the second by a short interval.

B) when the two impulses are close together on the membrane

69

Action potentials originate in the:
A) axon.
B) dendrites.
C) cell body.
D) axon hillock.

D) axon hillock

70

EPSPs on the distant dendrite’s tree:
A) have maximum influence on an action potential.
B) are easier to summate both spatially and temporally than EPSPs elsewhere.
C) are less likely to have a dynamic effect than those close to the axon hillock.
D) do not modulate action potentials.

C) are less likely to have a dynamic effect than those close to the axon hillock

71

Dendrites can receive:
A) excitatory input.
B) inhibitory input.
C) both excitatory and inhibitory input.
D) Dendrites send signals rather than receive them.

C) both excitatory and inhibitory input

72

EPSPs and IPSPs are first received by:
A) the soma.
B) the neuronal membrane.
C) dendrites.
D) the axon hillock.

C) dendrites

73

The ______ acts in a way similar to a democracy in that it “counts votes” from incoming EPSPs and IPSPs, and if there is enough excitation, an action potential will fire.
A) axon hillock
B) dendrite
C) soma
D) ion channel

A) axon hillock

74

_____ is the term used to denote reverse movement of the action potential into the dendrites.
A) EPSP reversal.
B) Back propagation.
C) Inverse IPSP.
D) None of the answers is correct.

B) Back propagation

75

______ combines genetics and light to control targeted cells in living tissue.
A) Photogenetics
B) Optogenetics
C) Infragenetics
D) None of the answers is correct

B) Optogenetics

76

Research on optogenetics and light-sensitive ion channels has discovered that channelrhodopsin-2 can be used to ______ neurons and halorhodopsin can be used to ______ neurons.
A) hyperpolarize; depolarize
B) depolarize; hyperpolarize
C) destroy; depolarize
D) depolarize; destroy

B) depolarize; hyperpolarize

77

Stretch-sensitive channels are typically found on the dendrites of:
A) motor neurons.
B) interneurons.
C) sensory neurons.
D) All of the answers are correct.

C) sensory neurons

78

Dendrites of touch-sensitive neurons are activated by:
A) stretching open Na+ channels.
B) stretching open K+ channels.
C) closing K+ channels.
D) closing Cl– channels.

A) stretching open Na+ channels

79

An end plate is found on:
A) a muscle membrane.
B) a dendrite membrane.
C) an axon.
D) touch receptors

A) a muscle membrane

80

The muscle end plate is activated by the neurotransmitter: A) serotonin.
B) norepinephrine.
C) dopamine.
D) acetylcholine

D) acetylcholine

81

The neurotransmitter-sensitive ion channels on muscle end plates differ from other ion channels in that:
A) they have a different resting membrane potential.
B) they allow only K+ to leave the neuronal membrane.
C) they allow only Cl– to leave the neuronal membrane.
D) K+ and Na+ enter and leave through the same channels.

D) K+ and Na+ enter and leave through the same channels.

82

Lou Gehrig’s disease is also known as:
A) multiple sclerosis.
B) arteriosclerosis.
C) amyotrophic lateral sclerosis.
D) poliomyelitis

C) amyotrophic lateral sclerosis

83

______ is a disease that has been linked with the death of ______.
A) Amyotrophic lateral sclerosis; sensory neurons
B) Myasthenia gravis; sensory neurons
C) Amyotrophic lateral sclerosis; spinal motor neurons
D) Myasthenia gravis; interneurons

C) Amyotrophic lateral sclerosis; spinal motor neurons

84

Alex is 53 years old and has had weakness in his throat and chest for a few months. Now he is also starting to have general weakness in his arms and legs. The weakness in his legs has gotten so bad that yesterday he fell down when walking across his living room. Alex appears to be showing early signs of:
A) Parkinson’s disease.
B) amyotrophic lateral sclerosis (ALS).
C) Huntington’s disease.
D) Alzheimer’s disease.

B) amyotrophic lateral sclerosis (ALS)