Deck 8: Synaptic Transmission and Neural Integration

Question 1

Histamine has receptors in the hypothalamus, RAS system, stomach, blood vessels, and bronchioles. What creates histamine's differing effects seen in each of these areas?

A)Histamine recombines with other endogenous substances once inside the target cell.
B)All of the effects are a result of membrane dehydration.
C)Each tissue is different, so no two can have the same effect.
D)They are dependent on which cell secretes the histamine.
E)There are different message transduction systems.

Answer 1

E

Question 2

At metabotropic receptors, a(n)

A)neurotransmitter binding to a receptor stimulates a G- protein, which then activates a second messenger through one or more enzymatic actions.
B)neurotransmitter binding to a receptor opens channels that are a separate protein from the receptor.
C)neurotransmitter binding to a receptor opens or closes channels that are part of the same protein as the receptor.
D)ion binding to a receptor opens channels in the plasma membrane.
E)neurotransmitter binding to a receptor opens or closes channels that are a separate protein from the receptor.

Answer 2

A

Question 3

Which of the following GABA receptor types is coupled to chloride channels?

A)GABAA only
B)GABAB only
C)GABAC only
D)both GABAA and GABAB
E)both GABAA and GABAC

Answer 3

A

Question 4

How does temporal summation create an action potential?

A)It is frequency modulated and of the same amplitude for intensity.
B)The temporal lobe in the brain stimulates EPSPs to trigger an action potential.
C)Generator potentials are at the same tempo on adjacent neurons.
D)Two or more postsynaptic potentials are generated in rapid succession at the same synapse before they can dissipate, thereby exceeding threshold.
E)Potentials are generated on several dendrites at the same time to trigger threshold and the production of an action potential.

Question 5

Divergence in neurophysiology refers to which of the following?

A)the presence of EPSPs and IPSPs on a neuron at the same time
B)the arrival of an action potential at the axon terminal
C)the level of depolarization required to generate an action potential
D)the communication of one neuron to several postsynaptic cells
E)the summation of graded potentials to determine whether or not an action potential will be generated

Question 6

The influx of calcium into the axon terminal of a chemical synapse is responsible for which of the following?

A)diffusion of the neurotransmitter across the membrane and into the cleft
B)movement of calcium through gap junctions
C)initiation of an action potential
D)fusion of vesicles to the membrane and of exocytosis neurotransmitter
E)termination of an action potential

Question 7

The neurotransmitter that is released from the presynaptic neuron must diffuse across the to reach the postsynaptic neuron.

A)dendrite
B)synaptic cleft
C)cell body
D)axon
E)axon hillock

Question 8

Most neurotransmitters are synthesized in what region of a neuron?

A)Golgi apparatus
B)rough endoplasmic reticulum
C)cytosol of the axon terminal
D)synaptic vesicles
E)axon hillock

Question 9

The most common mechanism for producing a fast EPSP involves which of the following?

A)closing of sodium- selective channels
B)opening of sodium- selective channels
C)closing of potassium- selective channels
D)opening of potassium- selective channels
E)opening of channels that permit both sodium and potassium to flow through

Question 10

The binding of a neurotransmitter to its receptor at an inhibitory synapse can lead to the of _ channels.

A)closing : chloride
B)opening : sodium
C)closure : potassium
D)opening : calcium
E)opening : potassium

Question 11

Figure 8.1
What is occurring in Step 2 of Figure 8.1, and how is that process originated?

A)fast receptor opens an ion channel that is part of the receptor : reuptake
B)slow receptor can open or close an ion channel by G protein coupling between receptor and ion channel : neurotransmitter release
C)receptor that can stimulate a cellular response by gating its ion channel : stimulating a G protein to gate an ion channel
D)influx of calcium : depolarization causes voltage- gated calcium channels to open
E)remove neurotransmitter from the synaptic cleft : reuptake

Question 12

Which of the following neurotransmitters is a neuropeptide?

A)glycine
B)substance P
C)norepinephrine
D)aspartate
E)acetylcholine

Question 13

The binding of a neurotransmitter to its receptor at an inhibitory synapse can lead to the of _ channels.

A)closure : chloride
B)opening : calcium
C)opening : chloride
D)closure : potassium
E)opening : sodium

Question 14

The extent of neurotransmitter binding to receptors on the postsynaptic membrane is determined primarily by which of the following?

A)the distance of the cleft
B)neurotransmitter vesicles
C)the concentration of neurotransmitter
D)sodium
E)calcium

Question 15

In the absence of active chloride ion transport, opening of chloride channels in a cell that has hyperpolarized will result in which of the following?

A)movement of chloride equally in both directions
B)net movement of chloride into the cell
C)net movement of chloride out of the cell
D)depolarization of the cell
E)absence of any chloride movement

Question 16

What type of receptor is responsible for the rapid opening of ion channels in response to the interaction between the ligand and receptor?

A)potentiotropic
B)ionotropic
C)metabotropic
D)chemotropic
E)mechanotropic

Question 17

What two enzymes catalyze the breakdown of catecholamines?

A)acetylcholinesterase and dopa decarboxylase
B)catechol- O- methyltransferase and acetylcholinesterase
C)dopa decarboxylase and phenylethanolamine N methyltransferase
D)monoamine oxidase and phenylethanolamine N methyltransferase
E)monoamine oxidase and catechol- O- methyltransferase

Question 18

What happens to the resting membrane potential of - 70 mV when sodium leak channels close?

A)returns to - 70 mV
B)repolarization
C)hyperpolarization
D)depolarization
E)membrane stabilization

Question 19

All of the following receptor sub- types are ionotropic, EXCEPT

A)GABAA
B)AMPA glutamatergic.
C)muscarinic cholinergic.
D)nicotinic cholinergic.
E)kainate glutamatergic.

Question 20

Which of the following neurotransmitters is an amino acid neurotransmitter released at excitatory synapses?

A)aspartate
B)substance P
C)acetylcholine
D)norepinephrine
E)glycine

Question 21

What ion directly triggers neurotransmitter release from the presynaptic neuron?

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

Question 22

Which of the following neurotransmitters is a catecholamine?

A)acetylcholine
B)glycine
C)norepinephrine
D)substance P
E)aspartate

Question 23

All of the following receptor sub- types are metabotropic, EXCEPT

A)nicotinic cholinergic.
B)alpha adrenergic.
C)muscarinic cholinergic.
D)beta adrenergic.
E)NMDA

Question 24

The synaptic delay is caused by the time required for which step of neurotransmitter release?

A)packaging of neurotransmitter into synaptic vesicles
B)calcium entry to trigger exocytosis
C)an action potential to move from axon hillock to axon terminal
D)the neurotransmitter to diffuse across the synaptic cleft
E)the synthesis of neurotransmitter

Question 25

Epinephrine binds best to which of the following receptor types?

A)alpha1 adrenergic receptors
B)alpha2 adrenergic receptors
C)alpha3 adrenergic receptors
D)beta1 adrenergic receptors
E)beta2 adrenergic receptors

Question 26

Which of the following statements about electrical synapses is FALSE?

A)Electrical synapses connect hypothalamic neurons that release tropic hormones.
B)Gap junctions are formed from proteins called connexins.
C)Electrical synapses are usually for small- response, single neuron firing.
D)Electrical synapses are found in the retina.
E)Electrical synapses are found in the brainstem.

Question 27

Neuropeptides are synthesized in what region of a neuron?

A)at the dendrite
B)within the vesicles
C)within the axon terminal
D)in the rough endoplasmic reticulum
E)along the axon

Question 28

Figure 8.1
Identify the structure on the postsynaptic membrane that bind with the neurotransmitter in Step 4 of Figure 8.1, and indicate its function.

A)a receptor that can stimulate a cellular response by gating its ion channel or stimulating a G protein to gate an ion channel
B)a voltage- gated calcium channel for reuptake of Ca2+
C)endocytotic vesicle storing neurotransmitter
D)transporter for the reuptake of released neurotransmitter
E)an enzyme used to remove neurotransmitter from the synaptic cleft

Question 29

What happens to the resting membrane potential of - 70 mV when sodium channels open?

A)hyperpolarization
B)repolarization
C)membrane stabilization
D)depolarization
E)returns to - 70 mV

Question 30

The rapid change in membrane potential that occurs when a ligand binds to an ionotropic receptor is caused by which of the following?

A)the large ion gradient across the membrane
B)the G protein amplification that causes the rapid channel response
C)the presence of that protein functioning as both an ionotropic receptor and as the ion channel
D)the rapid gating of the ion channel by G protein
E)the rapid G protein response that indirectly links receptor to channel

Question 31

What happens to the resting membrane potential of - 70 mV when channels, that permit both sodium and potassium to move through, open?

A)returns to - 70 mV
B)hyperpolarization
C)repolarization
D)depolarization
E)membrane stabilization

Question 32

The final integration of postsynaptic potentials that determines whether an action potential is generated occurs within what region of a neuron?

A)axon
B)axon hillock
C)dendrites
D)cell body
E)rough endoplasmic reticulum

Question 33

The chemical synapse is bounded by the neuron, from which neurotransmitters are released across the synaptic cleft, to the neuron, where the receptors for that neurotransmitter are located.

A)postsynaptic : presynaptic
B)terminal : presynaptic
C)parasynaptic : postsynaptic
D)presynaptic : parasynaptic
E)presynaptic : postsynaptic

Question 34

Neurotransmitter release occurs by what mechanism?

A)endocytosis
B)secondary active transport
C)diffusion
D)exocytosis
E)primary active transport

Question 35

What is a change in the postsynaptic potential that brings membrane potential closer to threshold called?

A)inhibitory presynaptic potential
B)hyperpolarizing postsynaptic potential
C)inhibitory postsynaptic potential
D)suprathreshold postsynaptic potential
E)excitatory postsynaptic potential

Question 36

As the amplitude of the excitatory postsynaptic potential increases above threshold, the time between each action potential will , thereby increasing the of the action potentials.

A)decrease : frequency
B)increase : frequency
C)not be altered : amplitude
D)increase : amplitude
E)decrease : amplitude

Question 37

Why are amino acid neurotransmitters NOT considered biogenic amines?

A)Amino acids lose their activity when stored, while biogenic amines do not.
B)Biogenic amines may be taken up by non- conducting cells, while amino acids are not.
C)Amino acids used to make biogenic amines are not used for anything else.
D)Amino acids are excitatory only, while biogenic amines are not.
E)Biogenic amines still contain an amine group, but are no longer amino acids.

Question 38

Which of the following compounds is NOT a neuropeptide?

A)epinephrine
B)vasopressin
C)endorphin
D)substance P
E)oxytocin

Question 39

Which enzyme catalyzes the synthesis of cAMP?

A)acetylcholinesterase
B)choline acetyl transferase
C)adenylate cyclase
D)catechol- O- methyltransferase
E)monoamine oxidase

Question 40

Neurons that synthesize and release acetylcholine are called neurons.

A)adrenergic
B)gamma
C)ACTH
D)cholinergic
E)dopaminergic

Question 41

Presynaptic modulation occurs at what type of synapse?

A)axodendritic
B)axoaxonic
C)axosomatic
D)dendrodendritic
E)dendrosomatic

Question 42

Which of the following is NOT a mechanism whereby neurotransmitters are rapidly removed from the synaptic cleft?

A)active reuptake across the presynaptic membrane
B)binding to the receptor
C)transport back up the axon to be immediately repackaged
D)diffusion out of the cleft
E)degradation by enzymes

Question 43

Fast EPSPs are produced at which of the following types of receptor?

A)nicotinic cholinergic only
B)alpha- adrenergic only
C)AMPA receptors only
D)both nicotinic cholinergic and AMPA receptors
E)both nicotinic cholinergic and alpha- adrenergic receptors

Question 44

Which of the following statements about inhibitory synapses is FALSE?

A)The postsynaptic cell is less likely to generate an action potential.
B)The membrane potential of the postsynaptic cell can be hyperpolarized.
C)In presynaptic inhibition, the lower level potential generated interferes with the oncoming action potential.
D)Opening of chloride channels can generate an IPSP.
E)Opening of potassium channels can generate an IPSP.

Question 45

The opening of a chloride channel acts to the development of an action potential at the axon hillock.

A)enhance
B)inhibit
C)facilitate
D)stimulate
E)further

Question 46

Neurotransmitters can be reused through the process of , where neurotransmitters are transported back across the presynaptic membrane.

A)resynthesis
B)reuptake
C)regeneration
D)recycling
E)receptor binding

Question 47

What enzyme catalyzes breakdown of catecholamines in the synaptic cleft only?

A)monoamine oxidase
B)acetylcholinesterase
C)adenylate cyclase
D)catechol- O- methyltransferase
E)choline acetyl transferase

Question 48

Synaptic potentials are produced at what type of synapse?

A)axoaxonic, axodendritic, and axosomatic synapses
B)axoaxonic and axodendritic synapses only
C)axoaxonic and axosomatic synapses only
D)pre- axon hillock synapses only
E)axodendritic synapses only

Question 49

What happens to the resting membrane potential of - 70 mV when channels for a cation with an equilibrium potential of - 30 mV open?

A)returns to - 70 mV
B)membrane stabilization
C)repolarization
D)hyperpolarization
E)depolarization

Question 50

Which of the following neurotransmitters is an amino acid neurotransmitter released at inhibitory synapses?

A)aspartate
B)norepinephrine
C)substance P
D)acetylcholine
E)glycine

Question 51

If the resting membrane potential is equal to chloride's equilibrium potential, in which direction will chloride ions move if chloride channels open while the cell remains at resting membrane potential?

A)inward
B)outward
C)No ions will move through the channel.
D)Ions will move equally in both directions.
E)Three chloride ions will move out for every two chloride ions that move in.

Question 52

Synaptic vesicles store

A)sodium.
B)neurotransmitter.
C)potassium.
D)calcium.
E)enzymes that degrade neurotransmitter.

Question 53

Which of the following couplings between neurotransmitter and neurotransmitter class is INCORRECT?

A)histamine : biogenic amine
B)adenosine : amino acid
C)nitric oxide : gas
D)norepinephrine : catecholamine
E)enkephalin : neuropeptide

Question 54

The action of adrenergic receptors identifies them as receptors.

A)ionotropic
B)mechanically- gated
C)chemotropic
D)metabotropic
E)voltage- gated

Question 55

The synthesis of acetylcholine involves an enzyme called , which is present within the axonal cytosol and is responsible for converting into acetylcholine + CoA.

A)acetylcholinesterase : choline
B)choline acetyl transferase : acetyl CoA + choline
C)choline acetyl transferase : acetyl CoA
D)acetylcholinesterase : acetyl CoA + choline
E)choline acetyl transferase : choline + acetate

Question 56

What enzyme catalyzes breakdown of catecholamines in the synaptic cleft and in the mitochondria of the axon terminal of the presynaptic cell?

A)monoamine oxidase
B)choline acetyl transferase
C)adenylate cyclase
D)catechol- O- methyltransferase
E)acetylcholinesterase

Question 57

The duration of a slow, excitatory postsynaptic potential mediated by cAMP is driven by the extent of time that cAMP remains active before being degraded by what protein?

A)G protein
B)protein kinase A
C)adenylate cyclase
D)protein kinase C
E)phosphodiesterase

Question 58

is an amino acid neurotransmitter at excitatory synapses whereas is an amino acid neurotransmitter at inhibitory synapses.

A)Gamma- aminobutyric acid : glutamate
B)Glycine : aspartate
C)Gamma- aminobutyric acid : glycine
D)Glutamate : aspartate
E)Aspartate : glycine

Question 59

Figure 8.1
In Figure 8.1, what is the event in Step 1 that is required to start the process that leads to the release of neurotransmitter from an axon terminal?

A)movement of sodium into the neuron and down the axon
B)movement of calcium down the axon
C)generator potential from the axon hillock
D)migration of newly synthesized neurotransmitter from the soma
E)action potential

Question 60

What happens to the resting membrane potential of - 70 mV when potassium channels close?

A)hyperpolarization
B)returns to - 70 mV
C)repolarization
D)membrane stabilization
E)depolarization

Question 61

The action of any chemical messenger ultimately depends not on the nature of the messenger, but rather on the

A)nerve cell stimulated.
B)half- life of the messenger.
C)affinity of the receptor.
D)signal transduction mechanism activated.
E)organ system activated.

Question 62

What type of receptor is both metabotropic and cholinergic?

A)dopaminergic
B)muscarinic
C)nicotinic
D)adrenergic
E)serotonergic

Question 63

An example of a slow excitatory postsynaptic potential that involves closure of potassium channels relies on cAMP produced by what enzyme?

A)protein kinase A
B)adenylate cyclase
C)G protein
D)protein kinase C
E)phosphodiesterase

Question 64

Which of the following would increase the likelihood of an action potential being generated in a postsynaptic cell?

A)opening of chloride channels on a postsynaptic cell that actively transports chloride ions out of the cell
B)opening of chloride channels on a postsynaptic cell with no active transport of chloride ions
C)opening of potassium channels on the postsynaptic cell
D)presynaptic excitation at an excitatory synapse
E)presynaptic inhibition at an excitatory synapse

Question 65

Which of the following statements about synapses is FALSE?

A)Most synapses in the nervous system are chemical synapses.
B)Communication across electrical synapses is bi- directional.
C)Communication at chemical synapses is slower than at electrical synapses.
D)Electrical synapses can be gated.
E)Neurotransmitters can move from one cell to another through gap junctions at an electrical synapse.

Question 66

Which of the following neurotransmitters is the most common neurotransmitter in the peripheral nervous system?

A)acetylcholine
B)glycine
C)substance P
D)norepinephrine
E)aspartate

Question 67

Which enzyme catalyzes the synthesis of acetylcholine?

A)acetylcholinesterase
B)monoamine oxidase
C)choline acetyl transferase
D)catechol- O- methyltransferase
E)adenylate cyclase

Question 68

What is the type of receptor present on the axon terminal that responds to the release of neurotransmitter from that same axon terminal?

A)nociceptor
B)autoreceptor
C)short loop receptor
D)reuptake receptor
E)paracrine receptor

Question 69

Convergence in neurophysiology refers to which of the following?

A)the communication of several neurons to one postsynaptic cell
B)the summation of graded potentials to determine whether or not an action potential will be generated
C)the presence of EPSPs and IPSPs on a neuron at the same time
D)the level of depolarization required to generate an action potential
E)the arrival of an action potential at the axon terminal

Question 70

Which of the following chemicals is NOT a known neurotransmitter?

A)carbon dioxide
B)ATP
C)acetylcholine
D)substance P
E)nitric oxide

Question 71

If the resting membrane potential is - 70 mV, which cation will move more frequently through a small cation channel?

A)calcium
B)hydrogen
C)magnesium
D)potassium
E)sodium

Question 72

What type of synapse occurs between an axon terminal of one neuron and the axon from another neuron?

A)axodendritic
B)somatoaxonic
C)axoaxonic
D)dendroaxonic
E)axosomatic

Question 73

In the presence of active chloride ion transport within a neuron, the opening of chloride channels will result in which of the following?

A)absence of any chloride movement
B)depolarization of the cell
C)net movement of chloride out of the cell
D)movement of chloride equally in both directions
E)net movement of chloride into the cell

Question 74

What enzyme catalyzes breakdown of acetylcholine?

A)catechol- O- methyltransferase
B)monoamine oxidase
C)choline acetyl transferase
D)adenylate cyclase
E)acetylcholinesterase

Question 75

For cells that communicate by electrical synapses, the message travels between cells via

A)the diffusion of neurotransmitters.
B)gap junctions.
C)ions moving across the synaptic cleft.
D)active transport across the synaptic cleft.
E)passive transport across the synaptic cleft.

Question 76

Presynaptic modulation of neurotransmitter release involves modifying at the axon terminal.

A)potassium channels
B)membrane potential
C)sodium channels
D)calcium influx
E)the vesicles selected for release

Question 77

What happens to the resting membrane potential of - 70 mV when channels for an anion with an equilibrium potential of - 80 mV open?

A)returns to - 70 mV
B)hyperpolarization
C)depolarization
D)repolarization
E)membrane stabilization

Question 78

Axoaxonic synapses are responsible for the extent of neurotransmitter released at the synapse.

A)modulating
B)decreasing
C)enhancing
D)inhibiting
E)increasing

Question 79

Once released, acetylcholine is degraded by extracellular enzymes into what product(s)?

A)acetyl CoA + choline
B)acetate only
C)choline only
D)methylcholine + acetate
E)acetate + choline

Question 80

Which adrenergic receptor(s)has the greatest affinity for norepinephrine?

A)alpha and beta1
B)alpha1 and beta
C)beta2
D)alpha2 and beta1, beta2
E)alpha3