Chapter 5: How Do Neurons Use Electrochemical Signals to Communicate and Adapt?

Question 1

______ is a neurotransmitter that slows down heart rate, whereas ______ speeds it up. A) Acetylcholine; norepinephrine B) Epinephrine; norepinephrine C) Norepinephrine; acetylcholine D) Epinephrine; acetylcholine

Answer 1

A) Acetylcholine; norepinephrine

Question 2

Acetylcholine helps ______ muscle contraction in the peripheral nervous system (PNS), whereas it acts to ______ muscle contraction in the central nervous system (CNS). A) excite; increase B) inhibit; slow down C) excite; inhibit D) inhibit; excite

Answer 2

D) inhibit; excite

Question 3

______ can also act as neurotransmitters. A) Synapses B) Mitochondria C) Hormones D) None of the answers is correct

Answer 3

C) Hormones

Question 4

Chemicals released by a neuron onto a target with an excitatory or inhibitory effect are called: A) messengers. B) action potentials. C) neurotransmitters. D) second messengers.

Answer 4

C) neurotransmitters.

Question 5

_____ is linked with shaking in the limbs, loss of balance, and general loss of muscular control. A) Parkinson’s disease B) Lou Gehrig’s disease C) Huntington’s disease D) All of the answers are correct

Answer 5

A) Parkinson’s disease

Question 6

Parkinson’s disease is linked with the loss of ______ neurons in the midbrain. A) acetylcholine B) dopamine C) norepinephrine D) serotonin

Answer 6

B) dopamine

Question 7

The structure of synapses is best viewed with a(n): A) electron microscope. B) light microscope. C) confocal microscope. D) Nissl-stained microscopic procedure.

Answer 7

A) electron microscope.

Question 8

______ contain the neurotransmitters. A) Synaptic vesicles B) Ribosomes C) Axons D) Dendrites

Answer 8

A) Synaptic Vesicles

Question 9

Electron microscopy is a useful tool in the study of synaptic morphology. The resolution of an electron microscope is much greater than that of a light microscope because: A) smaller electron waves scatter less than light waves. B) light waves scatter less than electron waves. C) larger electron waves scatter more than light waves. D) larger light waves scatter in patterns similar to those of electron waves.

Answer 9

A) smaller electron waves scatter less than light waves.

Question 10

A synaptic cleft is the space between: A) a synaptic vesicle and an axon terminal. B) a dendrite and an ion channel. C) an ion channel and an axon terminal. D) an axon terminal and a dendrite.

Answer 10

D) an axon terminal and a dendrite.

Question 11

______ contribute to chemical neurotransmission by supplying the building blocks for neurotransmitters or by cleaning up excess neurotransmitters. A) Glial cells B) Dendrites C) Receptors D) Neurons

Answer 11

A) Glial cells

Question 12

The contents of a synaptic vesicle include: A) neurotransmitters. B) structural proteins. C) DNA. D) neurotransmitters, structural proteins, and DNA.

Answer 12

A) neurotransmitters.

Question 13

Axon terminals are found on the ______ whereas dendritic spines are found on the ______. A) postsynaptic membrane; presynaptic membrane B) soma; neuron C) presynaptic membrane; postsynaptic membrane D) neuron; synapse

Answer 13

C) presynaptic membrane; postsynaptic membrane

Question 14

Neurons in which the ion channels from one cell connect directly with ion channels on another cell are called: A) gap junctions. B) electrical synapses. C) chemical synapses. D) Both gap junctions and electrical synapses are correct

Answer 14

D) Both gap junctions and electrical synapses are correct

Question 15

______ store several vesicles containing neurotransmitters. A) Storage granules B) Synaptic vesicles C) Transporter proteins D) Golgi bodies

Answer 15

A) Storage granules

Question 16

Which of the following would not be found at the axon terminal? A) mitochondria B) cell membrane C) synaptic vesicles D) axon hillock

Answer 16

D) axon hillock

Question 17

Electrical synapses: A) do not exist in mammals. B) are relatively rare in mammals. C) are roughly 50 percent of all mammalian synapses. D) are the prime mechanism of neurotransmission in mammals

Answer 17

B) are relatively rare in mammals.

Question 18

Compared with chemical synapses, electrical synapses: A) transmit messages faster. B) transmit messages more slowly. C) require more metabolic energy. D) do not require presynaptic activation.

Answer 18

A) transmit messages faster.

Question 19

There are more chemical synapses than electrical synapses in the mammalian nervous system because chemical synapses: A) transmit signals more quickly. B) allow better control of messages passed between neurons. C) send only excitatory signals. D) cannot be modified by learning.

Answer 19

B) allow better control of messages passed between neurons

Question 20

Precursor chemicals that form the building blocks for neurotransmitters are absorbed from the: A) mitochondria. B) blood. C) cell nucleus. D) Golgi apparatus.

Answer 20

B) blood.

Question 21

Protein molecules that pump substances across a membrane are called: A) microfilaments. B) microtubules. C) transporters. D) microvehicles

Answer 21

C) transporters.

Question 22

Neurotransmitters are produced in the: A) cell body. B) presynaptic terminals. C) Golgi body. D) cell body and presynaptic terminals.

Answer 22

D) cell body and presynaptic terminals.

Question 23

Voltage-gated calcium ion channels that function in neurotransmission are primarily found on the: A) postsynaptic membrane. B) presynaptic membrane. C) synaptic vesicles. D) dendrites.

Answer 23

B) presynaptic membrane.

Question 24

In order for neurotransmitters to be released, ______ must enter the terminal button. A) Na+ B) Ca2+ C) K+ D) Cl–

Answer 24

B) Ca2+

Question 25

Immediately before neurotransmission, calcium ions entering the presynaptic membrane bind to: A) calcitonin. B) calmodulin. C) calretinin. D) calpactin.

Answer 25

B) calmodulin.

Question 26

Ultimately Ca2+ serves to aid neural transmission by: A) causing an action potential. B) helping to make neurotransmitters. C) opening K+ channels on axon terminals. D) causing the release of neurotransmitter into the synaptic cleft.

Answer 26

D) causing the release of neurotransmitter into the synaptic cleft.

Question 27

Synaptic vesicles release neurotransmitters via: A) endocytosis. B) pinocytosis. C) exocytosis. D) phagocytosis.

Answer 27

C) exocytosis.

Question 28

Which of the following presynaptic events are in correct chronological order? A) calcium ion influx, action potential reaches axon terminal, vesicle fuses with membrane, diffusion of neurotransmitter B) action potential reaches axon terminal, calcium ion channels open, exocytosis, diffusion of neurotransmitter C) exocytosis, calcium ion influx, action potential reaches axon terminal, membrane depolarization D) action potential reaches axon terminal, calcium ion channels open, neurotransmitter diffusion, exocytosis

Answer 28

B) action potential reaches axon terminal, calcium ion channels open, exocytosis, diffusion of neurotransmitter

Question 29

When a neurotransmitter diffuses across the synaptic cleft and binds to a transmitter-activated receptor, which of the following may occur in the postsynaptic cell? A) membrane depolarization B) membrane hyperpolarization C) initiation of chemical reactions D) All of the answers are correct

Answer 29

D) All of the answers are correct.

Question 30

Receptors on the presynaptic side that may be influenced by neurotransmitters are called: A) autoreceptors. B) presynaptic receptors. C) presynaptic terminals. D) All of the answers are correct.

Answer 30

A) autoreceptors.

Question 31

For an action potential to be elicited: A) one quantum of neurotransmitter must be released from the presynaptic cell. B) multiple quanta of neurotransmitter must be released from the presynaptic cell. C) calcium ions must enter the postsynaptic cell. D) one quantum of neurotransmitter must be released from the presynaptic cell, and calcium ions must enter the postsynaptic cell.

Answer 31

B) multiple quanta of neurotransmitter must be released from the presynaptic cell.

Question 32

The number of quanta released from the presynaptic membrane is influenced by: A) the amount of Ca2+ that enters the presynaptic terminal. B) the number of vesicles docked at the presynaptic membrane. C) the number of receptors on the postsynaptic membrane. D) both the amount of Ca2+ that enters and the number of vesicles docked on the presynaptic side.

Answer 32

D) both the amount of Ca2+ that enters and the number of vesicles docked on the presynaptic side

Question 33

How is a neurotransmitter removed from the synaptic cleft? A) diffusion B) enzymatic degradation C) uptake by surrounding glial cells D) All of the answers are correct.

Answer 33

D) All of the answers are correct.

Question 34

_____ is the deactivation of a neurotransmitter by transporter proteins that bring the transmitter back into the presynaptic side for reuse. A) Diffusion B) Enzymatic degradation C) Reuptake D) Neurochemical recycling

Answer 34

C) Reuptake

Question 35

_____ is the process of neurotransmitter deactivation whereby the neurotransmitter simply leaves the synaptic cleft. A) Diffusion B) Enzymatic degradation C) Reuptake D) Glial uptake

Answer 35

A) Diffusion

Question 36

______ is the deactivation of a neurotransmitter in the synaptic cleft by enzymes. A) Reuptake B) Degradation C) Breakdown D) Decay

Answer 36

B) Degradation

Question 37

Reuptake is accomplished by: A) transporter proteins. B) glial cells. C) enzymes. D) both transporter proteins and glial cells

Answer 37

A) transporter proteins.

Question 38

Transmitters are usually released in the blood via: A) axodendritic synapses. B) axosomatic synapses. C) axosecretory synapses. D) axoaxonic synapses.

Answer 38

C) axosecretory synapses.

Question 39

______ synapses send signals from one dendrite to another dendrite. A) Axosomatic B) Axodendritic C) Dendodendritic D) Axosynaptic

Answer 39

C) Dendodendritic

Question 40

____ synapses send signals from an axon to a dendrite. A) Axosomatic B) Axodendritic C) Dendodendritic D) Axosynaptic

Answer 40

B) Axodendritic

Question 41

_____ synapses send signals from one axon to another axon. A) Axoaxonic B) Axodendritic C) Dendodendritic D) Axosynaptic

Answer 41

A) Axoaxonic

Question 42

_____ synapses are terminals that have no specific target. A) Axoextracellular B) Axosomatic C) Axodendritic D) Axosynaptic

Answer 42

A) Axoextracellular

Question 43

______ synapses send signals from an axon to a cell body. A) Axoextracellular B) Axosomatic C) Axodendritic D) Axosynaptic

Answer 43

B) Axosomatic

Question 44

When an axon terminal synapses on another axon terminal, it is called: A) an axosomatic synapse. B) an axoaxonic synapse. C) an axosynaptic synapse. D) an axodendritic synapse.

Answer 44

C) an axosynaptic synapse.

Question 45

Gap junctions are: A) axoaxonic synapses. B) dendodendritic synapses. C) somasomatic synapses. D) All of the answers are correct.

Answer 45

D) All of the answers are correct.

Question 46

Type II synapses are _____, whereas Type I synapses are_____. A) excitatory; inhibitory B) inhibitory, excitatory C) in the CNS; in the PNS D) in the brain; in the spinal cord

Answer 46

B) inhibitory, excitatory

Question 47

Which of the following best characterizes Type I and/or Type II synapses? A) Type I synapses are excitatory and have round synaptic vesicles. B) Type II synapses are inhibitory and have a greater postsynaptic density than Type I synapses. C) Type I synapses are inhibitory and have larger active zones than Type II synapses. D) Type II synapses are excitatory and have flattened synaptic vesicles.

Answer 47

A) Type I synapses are excitatory and have round synaptic vesicles.

Question 48

48. Type I synapses are found on the ______, while Type II synapses are found on the ______. A) spines or dendritic shafts of the neuron; neuron cell body B) neuron cell body; spines and dendritic shafts of the neuron C) axons and axon terminals; neuron cell body D) neuron cell body; axons and axon terminals

Answer 48

A) spines or dendritic shafts of the neuron; neuron cell body

Question 49

The active zone on Type I synapses is ______ when compared with the active zone on Type II synapses. A) smaller B) larger C) the same size D) of varying size

Answer 49

B) larger

Question 50

50. Which of the following statements regarding Type I and/or Type II synapses is not correct? A) Type II synapses have a larger active zones than Type I synapses. B) Type I synapses are located on dendritic spines. C) Type I synapses have round synaptic vesicles. D) Type II synapses have a narrower synaptic cleft.

Answer 50

A) Type II synapses have a larger active zones than Type I synapses.

Question 51

Which of the following criteria are used to determine if a substance is a neurotransmitter? I. The chemical must be synthesized in the neuron. II. When the neuron is active, the chemical is released and produces a response. III. Injection of the chemical mimics the effects of neuronal stimulation. IV. Mechanisms exist for the removal of the chemical. A) II, III, IV B) II and IV only C) I, II, III D) All of the answers are correct.

Answer 51

D) All of the answers are correct

Question 52

A chemical that has not yet met all the conditions that constitute a neurotransmitter is referred to as a(n): A) chemical signaler. B) secondary messenger. C) putative neurotransmitter. D) unclassified neurotransmitter.

Answer 52

C) putative neurotransmitter.

Question 53

A Renshaw loop consists of: A) an interneuron that inhibits the activity of a motor neuron. B) a sensory neuron that increases the activity of a motor neuron. C) an interneuron that increases the activity of a motor neuron. D) a sensory neuron that increases the activity of an interneuron.

Answer 53

A) an interneuron that inhibits the activity of a motor neuron.

Question 54

Which of the following is not a classification type of neurotransmitter? A) small molecule B) nucleic acid C) gas D) peptide

Answer 54

B) nucleic acid

Question 55

Which of the following is not part of the amine subtype of small-molecule neurotransmitters? A) dopamine B) glycine C) serotonin D) norepinephrine

Answer 55

B) glycine

Question 56

Acetylcholine is synthesized from acetate and choline by: A) choline acetyltransferase (ChAT). B) choline acetylbinderase (ChAB). C) tyrosine hydroxylase. D) histamine.

Answer 56

A) choline acetyltransferase (ChAT).

Question 57

Acetylcholine is deactivated through: A) reuptake. B) diffusion. C) enzymatic degradation. D) glial reuptake.

Answer 57

C) enzymatic degradation.

Question 58

The rate by which dopamine, epinephrine, and norepinephrine can be synthesized is controlled by a rate-limiting factor that is linked to the availability of: A) tryptophan. B) ChAT. C) tyrosine hydroxylase. D) histamine.

Answer 58

C) tyrosine hydroxylase.

Question 59

The rate-limiting factor of dopamine synthesis can be bypassed through the administration of: A) acetylcholine. B) L-dopa. C) tryptophan. D) norepinephrine.

Answer 59

B) L-dopa.

Question 60

Which of the following is not an amino acid neurotransmitter? A) dopamine B) glutamate C) histamine D) GABA

Answer 60

A) dopamine

Question 61

Which is the correct sequence of amine neurotransmitters? A) tyrosine, dopamine, L-dopa, epinephrine, norepinephrine B) L-dopa, tyrosine, dopamine, norepinephrine, epinephrine C) tyrosine, L-dopa, dopamine, epinephrine, norepinephrine D) tyrosine, L-dopa, dopamine, norepinephrine, epinephrine

Answer 61

D) tyrosine, L-dopa, dopamine, norepinephrine, epinephrine

Question 62

______ plays a role in regulating mood, appetite, aggression, and arousal. A) Norepinephrine B) Dopamine C) Acetylcholine D) Serotonin

Answer 62

D) Serotonin

Question 63

Which two neurotransmitters are synthesized from the same precursor molecule? A) glycine and dopamine B) glutamate and GABA C) histamine and serotonin D) acetylcholine and glycine

Answer 63

B) glutamate and GABA

Question 64

In the mammalian brain ______ is the main inhibitory neurotransmitter, and ______ is the main excitatory neurotransmitter. A) GABA; glycine B) GABA; glutamate C) glutamate; GABA D) glycine; glutamate

Answer 64

B) GABA; glutamate

Question 65

What is the predominant inhibitory neurotransmitter in the spinal cord? A) GABA B) glutamate C) glycine D) histamine

Answer 65

C) glycine

Question 66

In the nervous system, peptides play a role in: A) regulating feeding and drinking behavior. B) hormonal functions. C) pain and pleasure regulation. D) regulating feeding and drinking behavior, hormonal functions, and pain and pleasure regulation.

Answer 66

D) regulating feeding and drinking behavior, hormonal functions, and pain and pleasure regulation.

Question 67

Met-enkephalin, leu-enkephalin, and beta-endorphin are endogenous neuropeptides whose function is mimicked by: A) opium. B) dopamine. C) morphine. D) both opium and morphine.

Answer 67

D) both opium and morphine.

Question 68

In the popular movie Awakenings, ______ was used to treat patients with a rare movement disorder that followed a severe influenza outbreak in the 1920s. A) acetylcholine B) norepinehphrine C) L-dopa D) dopamine

Answer 68

C) L-dopa

Question 69

Unlike small-molecule neurotransmitters, peptide transmitters: A) do not bind directly to ion channels. B) directly alter the voltage of the postsynaptic cell. C) indirectly influence cell structure and function. D) do not bind directly to ion channels, but they indirectly influence cell structure and function

Answer 69

D) do not bind directly to ion channels, but they indirectly influence cell structure and function.

Question 70

____ are a class of neurotransmitters that can act as hormones for fertility, childbirth, and lactation. A) Peptides B) Amines C) Transmitter gases D) None of the answers is correct.

Answer 70

A) Peptides

Question 71

Nitric oxide (NO) is a gas neurotransmitter that: A) is stored in synaptic vesicles. B) is synthesized in the soma. C) dilates blood vessels in active areas. D) is degraded by digestive enzymes.

Answer 71

C) dilates blood vessels in active areas.

Question 72

Ionotropic receptors: A) change in shape when neurotransmitters bind to them. B) have no openings for ion diffusion. C) activate second messenger systems. D) are more metabolically expensive than metabotropic receptors.

Answer 72

A) change in shape when neurotransmitters bind to them.

Question 73

Ionotropic receptors consist of: A) a binding site. B) a pore. C) G proteins. D) both a binding site and a pore.

Answer 73

D) both a binding site and a pore.

Question 74

The opening of an ionotropic receptor can directly influence the movement of ______ ions across the neuronal membrane. A) Ca2+ B) Na+ C) K+ D) All of the answers are correct.

Answer 74

D) All of the answers are correct.

Question 75

Metabotropic receptors consist of: A) complex units of membrane-spanning proteins. B) a single membrane-spanning protein. C) a single non–membrane-spanning protein. D) complex units of non–membrane-spanning proteins.

Answer 75

B) a single membrane-spanning protein.

Question 76

Which of the following terms is not associated with metabotropic receptors? A) second messengers B) G proteins C) alpha subunits D) All of these terms are associated with metabotropic receptors.

Answer 76

D) All of these terms are associated with metabotropic receptors.

Question 77

A second-messenger system can: A) alter ion flow through the membrane channels. B) cause a series of reactions that result in the formation of new membrane ion channels. C) initiate the production of new proteins. D) All of the answers are correct.

Answer 77

D) All of the answers are correct.

Question 78

What chemicals are the first messenger? A) G proteins B) alpha subunits C) neurotransmitters D) sodium ions

Answer 78

C) neurotransmitters

Question 79

Neurotransmitters are identified by which of the following criteria? A) synthesis B) release C) receptor activation D) synthesis, release, and receptor activation

Answer 79

D) synthesis, release, and receptor activation

Question 80

Acetylcholine is the main neurotransmitter for: A) all skeletal motor synapses. B) 95 percent of skeletal motor synapses. C) half of skeletal motor synapses. D) no skeletal motor synapses.

Answer 80

A) all skeletal motor synapses.

Question 81

All neurons leaving the spinal cord have: A) acetylcholine as a neurotransmitter. B) dopamine as a neurotransmitter. C) GABA as a neurotransmitter. D) both dopamine and GABA as neurotransmitters.

Answer 81

A) acetylcholine as a neurotransmitter.

Question 82

______ activates the sympathetic nervous system, whereas ______ activates the parasympathetic nervous system. A) Norepinephrine; epinephrine B) Norepinephrine; acetylcholine C) Acetylcholine; norepinephrine D) Epinephrine; norepinephrine

Answer 82

B) Norepinephrine; acetylcholine

Question 83

Which of the following is not one of the activating systems in the CNS? A) glutamate B) dopamine C) norepinephrine D) acetylcholine

Answer 83

A) glutamate

Question 84

Which of the following activating system–cell body location pairs is not correct? A) Acetylcholine, basal forebrain B) Norepinephrine, locus coeruleus C) Dopamine, substantia nigra D) Serotonin, ventral tegmentum

Answer 84

D) Serotonin, ventral tegmentum

Question 85

Acetylcholine has been related to: A) depression. B) schizophrenia. C) Alzheimer’s disease. D) mania.

Answer 85

C) Alzheimer’s disease.

Question 86

Dopamine may be related to: A) depression. B) schizophrenia. C) Alzheimer’s disease. D) mania.

Answer 86

B) schizophrenia.

Question 87

Mania has been related to: A) acetylcholine. B) dopamine. C) norepinephrine. D) serotonin.

Answer 87

C) norepinephrine.

Question 88

Serotonin has been related to: A) depression. B) schizophrenia. C) Alzheimer’s disease. D) mania.

Answer 88

A) depression.

Question 89

Habituation is the result of: A) sensory neurons not being able to produce action potentials. B) motor neurons not being able to produce action potentials. C) excitatory postsynaptic potentials being smaller. D) both sensory and motor neurons not being able to produce action potentials.

Answer 89

C) excitatory postsynaptic potentials being smaller

Question 90

The neural basis of habituation: A) involves calcium ion influx decrease. B) involves calcium ion influx increase. C) occurs postsynaptically. D) involves calcium ion influx increase and occurs postsynaptically.

Answer 90

A) involves calcium ion influx decrease.

Question 91

Posttraumatic stress disorder (PTSD) has been linked with: A) an increased response to stimuli. B) a decreased response to stimuli. C) a decrease in acetylcholine. D) a decreased response to stimuli and a decrease in acetylcholine

Answer 91

A) an increased response to stimuli.

Question 92

The neural basis of sensitization: A) involves a decrease in calcium ion influx. B) involves an increase in calcium ion influx. C) takes place in potassium channels. D) involves an increase in calcium ion influx and takes place in potassium channels.

Answer 92

D) involves an increase in calcium ion influx and takes place in potassium channels.

Question 93

Repeated stimulation may cause: A) sensitization. B) habituation. C) associative behaviors. D) sensitization, habitation, and associative behaviors

Answer 93

D) sensitization, habitation, and associative behaviors.

Question 94

It has been found that in well-trained and habituated Aplysia, the number of sensory synapses: A) decreases but the size stays constant. B) stays constant but the size decreases. C) decreases and the size increases. D) decreases and the size decreases.

Answer 94

D) decreases and the size decreases.

Question 95

Increasing the number of synapses to account for learning involves _____, leading to the activation of _____, a second messenger. A) calcium; cGMP B) potassium; cAMP C) calcium; cAMP D) sodium; cGMP

Answer 95

C) calcium; cAMP

Question 96

In fruit flies, which mutation(s) may lead to impairments in the acquisition of habituation? A) dunce B) rutabaga C) collin D) dunce and rutabaga

Answer 96

D) dunce and rutabaga

Question 97

Which of the following statements is incorrect? A) Dendritic spines contain a variety of protein molecules. B) Dendritic spines are designed to act only in unison. C) Dendritic spines may appear or disappear on a dendrite in a matter of seconds. D) Dendritic spines, when forming a synapse, can change in size and shape and can even divide.

Answer 97

B) Dendritic spines are designed to act only in unison.