Deck 2: Synapses

Question 1

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

Answer 1

True

Question 2

 Inhibitory synapses actively suppress excitatory responses.

Answer 2

False

Question 3

 Professor Wick is teaching about neurotransmitter release and told his class that each neuron releases one kind of hormone.

Answer 3

False

Question 4

 Dr. Lattimer studies how the neurotransmitter dopamine is synthesized from tryptophan from the diet.

Question 5

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

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

Question 6

 Nitric oxide (NO) can function as a hormone.

Question 7

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

Question 8

 Most of the known neurotransmitters are synthesized from amino acids.

Question 9

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

Question 10

 Metabotropic synapses use a large variety of transmitters.

Question 11

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

Question 12

 Winnifred is in the lab drawing illustrations of neurons in her lab notebook. She labeled the specialized area between two neurons as the _____.

A) synapse
B) axon hillock
C) node of Ranvier
D) vesicle

Question 13

 Neurons communicate with both electrical and chemical signals. Scientists have shown that chemical communication is the preferred form as it is faster.

Question 14

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

Question 15

 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 16

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

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

Question 17

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

Question 18

 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 19

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

Question 20

 A reflex arc contains specialized motor neurons that detect and execute the reflex.

Question 21

 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 22

 Karissa is in the lab working and was able to produce a reflexive response by stimulating several different locations all at one time. She successfully demonstrated ______ summation.

A) spatial
B) reflexive
C) temporal
D) neuronal

Question 23

 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 24

 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 25

 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 26

 The neuron that receives the message is called the ______ neuron.

A) postsynaptic
B) presynaptic
C) polarized
D) reflexive

Question 27

 Latoya is working in the lab to generate an EPSP, which is a ______.

A) graded depolarization
B) graded hyperpolarization
C) reflex
D) specialized hormone

Question 28

 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 29

 Brock is working in the lab and has been able to demonstrate that ______.

A) the opening of sodium channels causes an EPSP
B) the opening of potassium channels causes an EPSP
C) the opening of sodium channels cases an IPSP
D) the opening of potassium channels causes an action potential

Question 30

 Maryanna is studying the reflex arc for a quiz. In her notes, she wrote down that the proper order is _____.

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 31

 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 32

 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 33

 Dr. Andrus studies reflexes and has demonstrated that a certain reflex doesn't occur if there is a single stimulus. He found that there needs to be _______ (several, rapidly produced stimuli) for the reflex to occur.

A) IPSPs
B) synaptic delay
C) temporal summation
D) spatial summation

Question 34

 Professor Kinsley is lecturing on EPSPs and action potentials. She tells the class that _____.

A) EPSPs are stronger than action potentials
B) sodium is required for an action potential but not for an EPSP
C) they are the same thing
D) EPSPs are decremental and action potentials are not

Question 35

 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 36

 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 37

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

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

Question 38

 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 39

 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 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

 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 42

 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 43

 A temporary hyperpolarization is known as an ____.

A) EPSP
B) IPSP
C) ISPS
D) EPIP

Question 44

 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 45

 Dr. Benzing is working in the lab. He has been able to demonstrate that ______ increases the frequency of the spontaneous firing rate.

A) EPSPs
B) IPSPs
C) EPSPs followed by IPSPs
D) simultaneous EPSPs and IPSPs

Question 46

 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 47

 Yasmine is in the lab trying to produce action potentials in her cultured neurons. What is most likely to work?

A) Using a chemical substance that will produce a large number of IPSPs.
B) Using electrical stimulation that will produce a large number of IPSPs.
C) Using electrical stimulation to produce a rapid sequence of EPSPs.
D) Using a chemical substance that will produce both EPSPs and IPSPs.

Question 48

 Professor Pholman is lecturing about the reflex arc. He tells his students that _____ in the ______ help coordinate contraction of certain muscles and relaxation of others.

A) motor neurons; spinal cord
B) interneurons; spinal cord
C) motor neurons; peripheral nervous system
D) sensory neurons; peripheral nervous system

Question 49

 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 50

 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 51

 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 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

 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 54

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

A) Sodium
B) Potassium
C) Calcium
D) Bicarbonate

Question 55

 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 56

 Toshia is working in the lab trying to produce an IPSP in her cultured neurons. What should she do?

A) Encourage sodium ions to enter the cell.
B) Encourage potassium ions to enter the cell.
C) Encourage chloride ions to leave the cell.
D) Encourage chloride ions to enter the cell.

Question 57

 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 58

 Professor Deshon is lecturing about ESPSs and IPSPs. He tells the class that in order to produce an IPSP, there needs to be an increase is permeability for _____.

A) chloride
B) calcium
C) sodium
D) carbon

Question 59

 Herb is watching a documentary on Dr. Loewi. He learned that neuroscientists first understood that synapses use chemicals to communicate because Dr. Loewi _____.

A) decreased a dog's heart rate and then used adrenaline to speed it up
B) stimulated a frog's heart that was in a fluid bath and then used just the fluid to simulate a second heart
C) measured the reflex speeds in dogs
D) applied adrenaline directly onto a heart muscle

Question 60

 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 61

 If Vonnie's body needed to dilate her blood vessels, it would release _____.

A) glutamate
B) nitric oxide
C) GABA
D) glycine

Question 62

 Lita has just eaten a lot of soy, which contains tryptophan. What should she try to consume less of to potentially increase tryptophan's entry to the brain?

A) Phenylalanine
B) Glucose
C) Insulin
D) Thiamine

Question 63

 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 64

 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 65

 Professor Russom is giving a talk about neurotransmitters. She tells the class that most neurotransmitters are synthesized from _____.

A) hormones
B) fatty acids
C) glucose
D) amino acids

Question 66

 Neuropeptides are synthesized in the ____.

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

Question 67

 Dopamine and norepinephrine are classified as ____.

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

Question 68

 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 69

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

A) Neuropeptides
B) Acetylcholine
C) Monoamines
D) Purines

Question 70

 Leeann is studying for a test on neurotransmission. She wrote in her notes that neurotransmitters are released from the presynaptic neuron when the action potential reaches the terminal and opens ______ channels.

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

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

 Luis is studying for a quiz on neurotransmission. He wrote in his notes that neurotransmitters are typically stored in _____ in the _____ neuron.

A) vesicles; presynaptic
B) dendrites; presynaptic
C) vesicles; postsynaptic
D) axons; presynaptic

Question 73

 What provides the building blocks for synthesizing nearly 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 74

 Vesicles are located ____.

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

Question 75

 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 76

 The amino acid tryptophan is the precursor to which neurotransmitter?

A) Dopamine
B) Endorphin
C) Serotonin
D) Nitric oxide

Question 77

 Paris is studying for a quiz on neurotransmitters. She should remember that all of the following are catecholamines except _____.

A) epinephrine
B) dopamine
C) norepinephrine
D) serotonin

Question 78

 Riva is unable to eat eggs, milk, and peanuts. She might have altered levels of _____ as a result.

A) nitric oxide
B) dopamine
C) glutamate
D) acetylcholine

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

 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.