Deck 4: Multiple Choice

Question 1

The speed of information flow in a nerve was first measured by:

A) Hermann von Helmholtz.
B) Wilder Penfield.
C) Eduard Hitzig.
D) Gustave Fritsch.

Answer 1

A

Question 2

Roberts Bartholow is remembered for being the first person to stimulate the brain of a:

A) dog.
B) rabbit.
C) human.
D) a dog and a rabbit.

Answer 2

C

Question 3

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.

Answer 3

B

Question 4

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.

Question 5

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 two microelectrodes in an axon and recording between them.

Question 6

The notion that opposites attract best describes:

A) a concentration gradient.
B) a voltage gradient.
C) diffusion.
D) All of the answers are correct.

Question 7

_____ is a neurological disorder that is linked to periods of excessive neural synchrony.

A) Epilepsy
B) Parkinson disease
C) Multiple sclerosis
D) Stroke

Question 8

An electroencephalogram,or EEG,can theoretically be recorded by:

A) a voltmeter.
B) a current meter.
C) an amp meter.
D) either a voltmeter or a current meter.

Question 9

Another term for volts is:

A) the difference in electrical potential between two poles.
B) current flow.
C) amps.
D) current flow and amps.

Question 10

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.

Question 11

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.

Question 12

Which of the following treatments is (are)used to help reduce epilepsy?

A) medication
B) deep brain stimulation
C) a high-fat,low-carbohydrate diet
D) All of the answers are correct.

Question 13

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.

Question 14

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.

Question 15

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.

Question 16

Erica is an 18-year-old 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 disease.
B) Parkinson disease.
C) epilepsy.
D) myasthenia gravis.

Question 17

Recording from single neurons was made possible by the invention of:

A) the electroencephalogram.
B) the oscilloscope.
C) the microelectrode.
D) the oscilloscope and the microelectrode.

Question 18

The technique of electrical stimulation was first discovered by:

A) Luigi Galvani.
B) René Descartes.
C) Gustave Fritsch and Edward Hitzig.
D) David Ferrier.

Question 19

René Descartes believed that _____ carried signals through the nervous system.

A) neurons
B) phlegm
C) the pineal gland
D) cerebrospinal fluid

Question 20

_____ won the Nobel Prize in 1963 for being the first to describe the electrical activity of neurons.

A) Young
B) von Helmholtz
C) Hodgkin and Huxley
D) Watson and Crick

Question 21

A change in the resting potential from -70 mV to -68 mV is called:

A) depolarization.
B) hyperpolarization.
C) graded excitatory potential.
D) nothing,as these changes occur spontaneously.

Question 22

Tetraethylammonium (TEA)

A) blocks potassium channels.
B) blocks sodium channels.
C) blocks chlorine channels.
D) neutralizes large protein molecules.

Question 23

The sodium-potassium pump _____ exchanges three _____ for two _____.

A) continuously;intracellular Na+;extracellular K+.
B) continuously;intracellular K+;extracellular Na+.
C) continuously;extracellular Na+;intracellular K+.
D) intermittently;intracellular K+;extracellular Na+.

Question 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

Question 25

Tetrodotoxin (puffer fish poison)mainly influences:

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.

Question 26

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.

Question 27

Small voltage fluctuations in the cell membrane that occur in the vicinity of the axon are called:

A) action potentials.
B) graded potentials.
C) ion fluctuations.
D) nerve impulses.

Question 28

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.

Question 29

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.

Question 30

At rest,the concentrations of _____ are higher inside of a neuron,whereas the concentrations of _____ are higher outside of a neuron.

A) potassium (K+);sodium (Na+)
B) sodium (Na+);potassium (K+)
C) potassium (K+);chloride (Cl-)
D) potassium (K+);anions (A-)

Question 31

Channels in the cell membrane are formed by:

A) sodium ions.
B) potassium ions.
C) protein molecules.
D) lipids.

Question 32

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-

Question 33

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 Cl- 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.

Question 34

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.

Question 35

The negative charge inside of the cell membrane is largely a product of the presence of negatively charged:

A) potassium ions.
B) sodium ions.
C) protein anions.
D) All of the answers are correct.

Question 36

There are approximately _____ as many K+ ions inside the cell as outside it.

A) 20 times
B) 2 times
C) one-tenth
D) half

Question 37

A change in the resting potential from -70 mV to -50 mV typically results in:

A) an excitatory postsynaptic potential.
B) repolarization.
C) an action potential.
D) hyperpolarization.

Question 38

Depolarization is primarily linked with _____,whereas hyperpolarization is mainly linked with _____.

A) sodium;calcium
B) potassium;sodium
C) sodium;chloride
D) chloride;potassium

Question 39

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.

Question 40

The neuronal membrane is best described as _____ such that _____ is (are)able to pass through.

A) impermeable;no ions
B) impermeable;sodium
C) semipermeable;sodium (Na+)and calcium (Ca+)
D) semipermeable;potassium (K+)and chloride (Cl-)

Question 41

Na+ and K+ channels on axons are mainly:

A) neurotransmitter dependent.
B) voltage dependent.
C) calcium dependent.
D) both neurotransmitter and voltage dependent.

Question 42

The magnitude of an action potential (AP)is measured near the axon hillock using an electrode and then measured again 2 mm farther down the axon.Compared to the AP measured near the axon hillock,the AP 2 mm farther down the axon is:

A) larger.
B) smaller.
C) of the same magnitude.
D) completely nullified.

Question 43

Which of the following is NOT one of the important reasons for refractory periods in neurons?

A) It limits the firing rate of the neuron.
B) It forces nerve impulses to travel in one direction.
C) It increases the sensitivity of the neuron.
D) It allows time for the neuron to reset prior to another action potential.

Question 44

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.

Question 45

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.

Question 46

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

Question 47

Because of refractory periods,the maximum firing rate of a neuron is approximately _____ impulses per second.

A) 500
B) 1000
C) 100
D) 200

Question 48

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.

Question 49

During an action potential:

A) the voltage of the cell membrane drops to zero and then returns to -70 mV.
B) the voltage of the cell membrane drops to zero,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.

Question 50

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

Question 51

_____ channels are less sensitive than _____ channels,so during an action potential they open more slowly but remain open longer.

A) calcium;sodium
B) sodium;potassium
C) chloride;sodium
D) potassium;sodium

Question 52

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.

Question 53

The domino effect best describes:

A) the absolute refractory period.
B) the nerve impulse.
C) the relative refractory period.
D) the resting membrane potential.

Question 54

Sodium channels close when the membrane potential reaches approximately:

A) +50 mV.
B) +30 mV.
C) -50 mV.
D) 0 mV.

Question 55

_____ produce(s)myelin in the peripheral nervous system,whereas _____ produce(s)myelin in the central nervous system.

A) Ependymal cells;Schwann cells
B) Astroglia;oligodendroglia
C) Oligodendroglia;Schwann cells
D) Schwann cells,oligodendroglia

Question 56

_____ 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.

Question 57

The voltage of a neural membrane that is sufficient to cause an action potential is approximately _____;it is called a(n)_____.

A) -70 mV;resting potential
B) -50 mV;graded potential
C) -65 mV;threshold potential
D) -50 mV;threshold potential

Question 58

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.

Question 59

Voltage-sensitive sodium channels are active:

A) whenever the cell membrane starts to depolarize.
B) when the voltage across the membrane reaches zero.
C) when the threshold voltage of the cell is reached.
D) when the voltage across the membrane reaches +30 mV.

Question 60

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.

Question 61

Myelin is important for propagating action potentials (AP)because:

A) it increases the AP's conduction speed.
B) it reduces the need for sodium and potassium.
C) it conserves energy.
D) it both increases the AP's conduction speed and conserves energy.

Question 62

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.

Question 63

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.

Question 64

Excitatory postsynaptic potentials (EPSPs)are recorded:

A) at the synaptic knob.
B) in the axon.
C) in the dendrites.
D) from the cell body.

Question 65

Multiple sclerosis is thought to be:

A) an autoimmune disease.
B) related to vitamin D.
C) related to genetic risk factors.
D) All of the answers are correct.

Question 66

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.

Question 67

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.

Question 68

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

Question 69

Action potentials originate in the:

A) axon.
B) dendrites.
C) cell body.
D) initial segment (axon hillock).

Question 70

On larger myelinated axons,nerve impulses can reach speeds of up to _____ meters per second.

A) 100
B) 50
C) 120
D) 30

Question 71

For an EPSP to cause another action potential,the stimulation must reach the _____,which is (are)rich in voltage-sensitive ion channels.

A) initial segment (axon hillock)
B) cell body
C) dendrites
D) terminal buttons

Question 72

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.

Question 73

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.

Question 74

EPSPs are associated with _____,whereas IPSPs are associated with _____.

A) opening of sodium channels;opening of potassium channels
B) opening of sodium channels;closing of potassium channels
C) closing of sodium channels;opening of potassium channels
D) opening of calcium channels;closing of potassium channels

Question 75

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.

Question 76

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.

Question 77

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.

Question 78

Simultaneous stimulation at two locations on a cell membrane that leads to an EPSP is an example of:

A) spatial summation.
B) temporal summation.
C) both spatial and temporal summation.
D) neither spatial nor temporal summation.

Question 79

Melissa,a 23-year-old woman,has been having tingling sensations in her right arm and leg for a few weeks.Today,when she woke up,she realized that she could barely move her right arm.She had a similar set of symptoms a couple of years ago,but they went away,so she thought everything was fine.Your advice to Melissa is to go to the doctor because:

A) she may have the flu.
B) she may have a brain tumor.
C) she may have multiple sclerosis.
D) she may have Huntington disease.

Question 80

The symptoms of multiple sclerosis are caused by:

A) excess myelin on axons.
B) loss of myelin around axons.
C) excess excitatory input.
D) excess inhibitory input.