Deck 2: Synapses

Question 1

Generally speaking,a neuron will release a greater number of neurotransmitters than what it will respond to with its own receptors.​

Answer 1

False

Question 2

Electrical communication between neurons is faster than chemical communication within neurons.​

Answer 2

True

Question 3

Transmission of information between neurons occurs in the same way as transmission along an axon.​

Answer 3

False

Question 4

Most neurons release more than one kind of neurotransmitter.​

Question 5

Most of the brain's excitatory ionotropic synapses use the neurotransmitter glutamate.​

Question 6

Gases can be used as neurotransmitters.​

Question 7

Specialized junctions between neurons are called ____.​

A)nodes of Ranvier
B)​spines
C)​dendrites
D)synapses

Question 8

The circuit from sensory neuron to muscle response is called ____.​

A)a reflex arc
B)​a synapse
C)​flexion
D)extension

Question 9

Spatial summation is the result of synaptic inputs from different locations arriving at the same time.​

Question 10

Inhibitory synapses actively suppress excitatory responses.​

Question 11

Most of the known neurotransmitters are synthesized from amino acids.​

Question 12

Whether or not a neurotransmitter is excitatory depends on the response of the postsynaptic receptor.​

Question 13

On the basis of what evidence were the properties of synapses first inferred?​

A)the electron microscope
B)​single-neuron recordings
C)​behavioral observations
D)PET scans

Question 14

Sherrington studied ____,which are automatic muscular responses to stimuli.​

A)instincts
B)​reflexes
C)​inhibitions
D)aversions

Question 15

Only sensory neurons are found in a reflex arc.​

Question 16

Metabotropic synapses use a large variety of transmitters.​

Question 17

The amount of temporal summation depends on the rate of stimulation.​

Question 18

At synapses,the cell that receives the message is called the presynaptic neuron.​

Question 19

Neurotransmitter levels in the brain can be affected by changes in diet.​

Question 20

Charles S.Sherrington was the first to infer the properties of ____.​

A)synapses
B)​the refractory period
C)​the sodium-potassium pump
D)dendrites and axons

Question 21

What do temporal summation and spatial summation have in common?​

A)Both involve the activity of only two neurons.
B)​Both require a response from the brain.
C)​Both depend on a combination of visual and auditory stimuli.
D)Both enable a reflex to occur in response to weak stimuli.

Question 22

A certain weak stimulus produces no reflexive response,but a rapid repetition of that stimulus may produce such a response.What is this phenomenon called?​

A)spatial summation
B)​temporal summation
C)​saltatory conduction
D)synaptic combination

Question 23

Sherrington found that repeated stimuli within a brief time have a cumulative effect.He referred to this phenomenon as ____.​

A)temporal summation
B)​spatial summation
C)​synaptic summation
D)saltatory summation

Question 24

What is the primary difference between temporal summation and spatial summation?​

A)Only spatial summation can produce an action potential.
B)​Spatial summation depends on contributions from more than one sensory neuron.
C)​Temporal summation produces a hyperpolarization instead of a depolarization.
D)Spatial summation alters the response of more than one postsynaptic cell.

Question 25

Temporal summation most likely occurs with ____.​

A)infrequent, subthreshold excitation
B)​rapid succession of stimuli that each exceed threshold
C)​infrequent, inhibitory stimuli
D)rapid succession of subthreshold excitation

Question 26

The primary difference between an EPSP and an action potential is that ____.​

A)the magnitude of an action potential decreases as it travels along the membrane
B)​EPSPs occur without sodium ions entering the cell
C)​action potentials are always hyperpolarizations
D)EPSPs are subthreshold events that decay over time and space

Question 27

Charles Sherrington would most likely agree with which statement about reflexes?​

A)The overall speed of conduction through a reflex arc is faster than conduction along an axon.
B)​Repeated stimuli occurring within a brief time can have a cumulative effect.
C)​Each neuron physically merges with the next one during a reflexive response.
D)Excitatory synapses are more important than inhibitory synapses.

Question 28

Which statement is TRUE of EPSPs?​

A)They work in pairs to produce an action potential.
B)​They decay over time and space.
C)​They can be either excitatory or inhibitory.
D)They occur because potassium gates open.

Question 29

Sherrington deduced that transmission at a synapse must be slower than conduction along an axon.This was based on what kind of evidence?​

A)temporal summation
B)​drugs that increase or inhibit activity at synapses
C)​the speed of reflexive responses
D)differences in diameter between axons and dendrites

Question 30

Why is the speed of conduction through a reflex arc slower than the speed of conduction of an action potential along an axon?​

A)Transmission between neurons at synapses is slower than along axons.
B)​The longer an axon, the slower its velocity.
C)​Interneurons have thicker axons than other neurons.
D)There are greater amounts of myelin involved in the reflex arc.

Question 31

An EPSP is a(n)____.​

A)graded depolarization
B)​depolarization with a rebounding hyperpolarization
C)​graded hyperpolarization
D)action potential in a reflex arc

Question 32

A graded depolarization is known as an ____.​

A)EPIP
B)​IPSP
C)​ESPN
D)EPSP

Question 33

What is the proper ordering of a reflex arc?​

A)motor neuron, sensory neuron, interneuron.
B)​sensory neuron, motor neuron, interneuron.
C)​motor neuron, interneuron, sensory neuron.
D)sensory neuron, interneuron, motor neuron.

Question 34

Which process indicates spatial summation?​

A)Present two or more weak stimuli at the same time.
B)​Start action potentials at both ends of one axon at the same time.
C)​Do not allow a flexor muscle to relax before stimulating it again.
D)Present a rapid sequence of weak stimuli.

Question 35

Spatial summation refers to ____.​

A)multiple weak stimulations that occur in rapid succession
B)​a decrease in responsiveness after repeated stimulation
C)​multiple weak stimulations that occur at the same time
D)an increase in the strength of action potentials after repeated stimulation

Question 36

To measure temporal summation in single cells,researchers ____.​

A)attach electrodes to the scalp
B)​insert an microelectrode into the scalp
C)​collect sodium and potassium ions from nearby glial cells
D)record depolarizations of the postsynaptic neuron

Question 37

Simultaneous weak stimuli at different locations produce a greater reflexive response than one of the stimuli by itself.What is this phenomenon called?​

A)Sherrington's law
B)​temporal summation
C)​spatial summation
D)the all-or-none law

Question 38

Temporal summation is to ____ as spatial summation is to ____.​

A)time; location
B)​EPSP; IPSP
C)​location; time
D)depolarization; hyperpolarization

Question 39

What causes an EPSP?​

A)the deactivation of cytoplasmic enzymes
B)​the opening of sodium channels
C)​the opening of potassium channels
D)the deactivation of stress response pathways

Question 40

Depolarization is to ____ as hyperpolarization is to ____.​

A)excitation; inhibition
B)​inhibition; excitation
C)​increasing the threshold; decreasing the threshold
D)decreasing the threshold; increasing the threshold

Question 41

Even at rest,most neurons have periodic production of action potentials,known as the ____.​

A)spontaneous firing rate
B)​excitatory firing rate
C)​all-or-none law
D)law of compensation

Question 42

A normal,healthy animal never contracts the flexor muscles and the extensor muscles of the same leg at the same time.Why not?​

A)When the interneuron sends excitatory messages to one, inhibitory messages go to the other.
B)​Both muscles are mechanically connected in a way that makes it impossible for both to contract at the same time.
C)​Such coordination is learned through prenatal movement.
D)Both muscles are controlled by branches of the same axon.

Question 43

The "decision" for a neuron to fire is determined by the ____.​

A)number of EPSPs only
B)​spontaneous firing rate
C)​number of IPSPs only
D)ratio of EPSPs to IPSPs

Question 44

An IPSP represents ____.​

A)the location where a dendrite branches
B)​a gap in a myelin sheath
C)​a subthreshold depolarization
D)a temporary hyperpolarization

Question 45

Which statement is TRUE about the spontaneous firing rates of neurons?​

A)EPSPs increase the frequency.
B)​EPSPs decrease the frequency.
C)​IPSPs increase the frequency.
D)One EPSP equals the effect of two IPSPs.

Question 46

An EPSP is to ____ as an IPSP is to ____.​

A)hyperpolarization; depolarization
B)​depolarization; hyperpolarization
C)​spatial summation; temporal summation
D)temporal summation; spatial summation

Question 47

Increased permeability to ____ would most likely result in an IPSP.​

A)sodium
B)​potassium
C)​calcium
D)bicarbonate

Question 48

Increased permeability to which type of ion would most likely result in an IPSP?​

A)sodium
B)​potassium
C)​calcium
D)bicarbonate

Question 49

In a reflex arc,the coordination between contraction of certain muscles and relaxation of others is mediated by ____.​

A)glial cells
B)​motor neurons
C)​sensory neurons
D)interneurons

Question 50

Which pattern of post-synaptic excitation will most likely result in an action potential?​

A)rapid sequence of EPSPs
B)​rapid sequence of IPSPs
C)​large number of simultaneous IPSPs
D)large number of simultaneous IPSPs and EPSPs

Question 51

​Loewi demonstrated that synapses operate by the release of chemicals by ____.

A)applying adrenaline directly to the heart muscle
B)​collecting fluid from a stimulated frog's heart, transferring it to another frog's heart, and measuring that heart rate
C)​measuring the speed of a dog's reflexes while the dog was under the influence of various drugs
D)applying an extract of marijuana in eye drops and discovering that it dilated the pupils

Question 52

What determines whether a neuron has an action potential?​

A)only the number of EPSPs impinging on an axon
B)​only the number of IPSPs impinging on the dendrites
C)​the combined effects of EPSPs and IPSPs
D)summation effects of IPSPs

Question 53

The research that firmly established synaptic communication as chemical was ____.​

A)Elliot's adrenaline mimicking sympathetic activation
B)​Loewi's transfer of fluid from stimulated frog hearts
C)​Sherrington's study of reflexes
D)Eccles's measurement of IPSPs

Question 54

The "spontaneous firing rate" of a neuron refers to ____.​

A)its resting potential
B)​its rate of energy consumption
C)​its rate of producing action potentials even when it is not stimulated
D)the velocity of its action potentials under normal conditions

Question 55

Inhibitory synapses on a neuron ____.​

A)hyperpolarize the postsynaptic cell
B)​weaken the cell's polarization
C)​increase the probability of an action potential
D)move the potential closer to the cell's threshold

Question 56

Which one of Sherrington's inferences about the synapse was WRONG?​

A)Transmission at a synapse is slower than transmission of impulses along an axon.
B)​Transmission at the synapse is primarily an electrical process.
C)​Synapses can be either excitatory or inhibitory.
D)Synapses make spatial summation and temporal summation possible.

Question 57

Which process will most likely result in an IPSP?​

A)potassium ions entering the cell
B)​sodium ions entering the cell
C)​chloride ions entering the cell
D)chloride ions leaving the cell

Question 58

When a vertebrate animal contracts the flexor muscles of a leg,it relaxes the extensor muscles of the same leg.Sherrington considered this evidence for the existence of ____.​

A)spatial summation
B)​temporal summation
C)​inhibitory messages
D)the delay in transmission at synapses

Question 59

A temporary hyperpolarization is known as an ____.​

A)EPSP
B)​IPSP
C)​ISPS
D)EPIP

Question 60

What ordinarily prevents extensor muscles from contracting at the same time as flexor muscles?​

A)the ligaments and tendons that bind them together
B)​learned patterns of coordination in the cerebral cortex
C)​inhibitory synapses in the spinal cord
D)control of both muscles by different branches of the same axon

Question 61

When an action potential reaches the end of an axon,it evokes the release of neurotransmitters by opening ____ channels in the axon terminal.​

A)chloride
B)​bicarbonate
C)​calcium
D)oxygen

Question 62

The catecholamines include ____.​

A)epinephrine, norepinephrine, dopamine, and serotonin
B)​epinephrine, serotonin, and dopamine
C)​dopamine, serotonin, and acetylcholine
D)epinephrine, norepinephrine, and dopamine

Question 63

The amino acid tryptophan is the precursor to which neurotransmitter?​

A)dopamine
B)​endorphin
C)​serotonin
D)nitric oxide

Question 64

You are eating a food containing tryptophan.What can you consume with it to increase its entry to the brain?​

A)phenylalanine
B)​carbohydrates
C)​fats
D)thiamine

Question 65

Insulin increases the entry of tryptophan into the brain by ____.​

A)weakening the blood-brain barrier
B)​converting tryptophan into a compound that more easily enters the brain
C)​increasing metabolic activity only in those areas of the brain that use tryptophan
D)causing certain competing amino acids to enter other cells, outside the brain

Question 66

Vesicles are located ____.​

A)in postsynaptic terminals
B)​in dendrites
C)​in presynaptic terminals
D)outside of the neuron in the extracellular fluid

Question 67

The basic building blocks for the majority of neurotransmitters are ____.​

A)amino acids
B)​nitric oxide
C)​sugars
D)carbohydrates

Question 68

What provides the building blocks for synthesizing all neurotransmitters?​

A)proteins found in the diet
B)​breakdown products of DNA
C)​breakdown products formed from other transmitters
D)methane and ethanol

Question 69

Which neurotransmitter is released by stimulated neurons to dilate the blood vessels?​

A)endorphins
B)​glycine
C)​nitric oxide
D)acetylcholine

Question 70

Which category of chemicals includes adenosine and several of its derivatives?​

A)neuropeptides
B)​acetylcholine
C)​monoamines
D)purines

Question 71

In addition to influencing other neurons,____ increases blood flow to a specific area of the brain.​

A)endorphins
B)​glycine
C)​nitric oxide
D)acetylcholine

Question 72

After one frog's heart has been stimulated,an extract of fluid from that heart can make a second frog's heart beat faster.What conclusion did Otto Loewi draw from these results?​

A)Transmission at synapses is a chemical event.
B)​The sympathetic and parasympathetic nervous systems are antagonistic.
C)​Transmission at heart muscle synapses is electrical.
D)Hormones facilitate the actions of the nervous system.

Question 73

Avoiding foods with lecithin,such as eggs and peanuts,would affect the levels of which neurotransmitter the most?​

A)acetylcholine
B)​serotonin
C)​GABA
D)endorphin

Question 74

Neuropeptides are synthesized in the ____.​

A)postsynaptic terminal
B)​presynaptic terminal
C)​cell body
D)dendrites

Question 75

What makes nitric oxide unique among neurotransmitters?​

A)It is released before the action potential occurs.
B)​It is taken back up into the presynaptic neuron.
C)​It is a gas.
D)It is an organelle.

Question 76

The presynaptic terminal stores high concentrations of neurotransmitter molecules in ____.​

A)axons
B)​vesicles
C)​peptides
D)dendrites

Question 77

​On advantage of nitric oxide is that it ____.

A)can be made by neurons efficiently
B)​is easily synthesized in a laboratory
C)​increases the growth of microglia
D)safe for human cells in large quantities

Question 78

What do dopamine,norepinephrine,and epinephrine share in common?​

A)They all affect the same receptors.
B)​They are all synthesized from the same amino acids.
C)​They are all released by the same neurons.
D)They all are gases.

Question 79

Although slower than an action potential,synaptic transmission is still relatively fast because ____.​

A)the synaptic cleft is very narrow
B)​sodium ions are transported quickly
C)​neurotransmitters diffuse faster than electricity
D)EPSPs travel faster than IPSPs

Question 80

Dopamine and norepinephrine are classified as ____.​

A)second messengers
B)​purines
C)​proteins
D)catecholamines