Deck 8: Synaptic Transmission and Neural Integration

Question 1

Synaptic vesicles store

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

Answer 1

B

Question 2

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

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

Answer 2

E

Question 3

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

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

Answer 3

A

Question 4

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

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

Question 5

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

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

Question 6

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

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

Question 7

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

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

Question 8

Which of the following statements about synapses is FALSE?

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

Question 9

The chemical synapse is bounded by the released across the synaptic cleft, to the neurotransmitter are located.

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

Question 10

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

Question 11

Neurotransmitter release occurs by what mechanism?

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

Question 12

Voltage -gated calcium channels in the axon terminal open in response to which of the following?

A) summation of graded potentials at the axon hillock
B) paracrines released from the post -synaptic cell
C) initiation of an action potential in the axon hillock
D) neurotransmitter binding to receptor
E) arrival of an action potential at the axon terminal

Question 13

Which of the following statements about electrical synapses is FALSE?

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

Question 14

Most neurotransmitters are synthesized in what region of a neuron?

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

Question 15

Neurotransmitters can be reused through the process of transported back across the presynaptic membrane.

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

Question 16

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) degradation by enzymes
C) diffusion out of the cleft
D) transport back up the axon to be immediately repackaged
E) binding to the receptor

Question 17

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) the synthesis of neurotransmitter
D) an action potential to move from axon hillock to axon terminal
E) the neurotransmitter to diffuse across the synaptic cleft

Question 18

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

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

Question 19

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

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

Question 20

What type of ion channels is necessary for the function of the axon and the axon terminal?

A) voltage -gated
B) chemically -gated
C) receptor -gated
D) mechanically -gated
E) ligand -gated

Question 21

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

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

Question 22

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

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

Question 23

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

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

Question 24

Fast excitatory responses not only occur quickly, but they

A) remain active for a long period of time.
B) are maintained for minutes to hours.
C) end quickly.
D) always create a substantial depolarization.
E) also have a slow component.

Question 25

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 or closes channels that are part of the same protein as the receptor.
C) neurotransmitter binding to a receptor opens channels that are a separate protein from 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.

Question 26

Metabotropic receptor -induced gating of ion channels requires more time to occur because of which of the following?

A) Ion channels linked to metabotropic receptors must move to the membrane before gating.
B) Their gating is linked to a G protein.
C) The channels are slower to open.
D) Intracellular calcium must increase before those channels will open.
E) Metabolic byproducts are required to open those channels.

Question 27

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

Question 28

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 29

Divergence in neurophysiology refers to which of the following?

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

Question 30

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

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

Question 31

What ion directly triggers neurotransmitter release from the presynaptic neuron?

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

Question 32

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

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

Question 33

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

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

Question 34

Convergence in neurophysiology refers to which of the following?

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

Question 35

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

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

Question 36

Presynaptic modulation occurs at what type of synapse?

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

Question 37

In the absence of an active chloride transporter in the plasma membrane, chloride acts to membrane potential by resisting any change in membrane potential.

A) depolarize
B) modify
C) stabilize
D) alter
E) hyperpolarize

Question 38

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 39

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

Question 40

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

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

Question 41

Suprathreshold graded potentials within a neuron can generate action potential(s) at the axon hillock, which allows for the

A) multiple : frequency coding
B) a single : frequency coding
C) several : amplitude coding
D) a single : amplitude coding
E) multiple : amplitude coding

Question 42

Presynaptic modulation of neurotransmitter release involves modifying terminal.

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

Question 43

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

Question 44

What is transported back into the axon terminal of cholinergic neurons to be resynthesized into active neurotransmitter?

A) acetyl CoA
B) acetylcholine
C) acetate
D) choline
E) epinephrine

Question 45

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

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

Question 46

What type of receptor is both ionotropic and cholinergic?

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

Question 47

For ionotropic receptors, their same neuron will summate.

A) slow : increases
B) rapid : increases
C) rapid : decreases
D) rapid : does not affect
E) slow : decreases

Question 48

Neurons that synthesize and release acetylcholine are called

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

Question 49

During presynaptic inhibition, the release of a neurotransmitter from the modulating neuron causes which of the following?

A) an IPSP on the postsynaptic cell
B) an EPSP on the postsynaptic cell
C) an increase in neurotransmitter release from the neuron it is modulating
D) a decrease in calcium entry into the axon terminal of the neuron it is modulating
E) a hyperpolarization of the neuron it is modulating

Question 50

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

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

Question 51

Which of the following statements about inhibitory synapses is FALSE?

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

Question 52

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

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

Question 53

Axoaxonic synapses are responsible for synapse.

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

Question 54

Biogenic amines are synthesized in what region of a neuron?

A) axon hillock
B) extracellular space
C) rough endoplasmic reticulum
D) cytosol of the axon terminal
E) cytosol of the cell body

Question 55

What type of receptor is both metabotropic and cholinergic?

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

Question 56

Which of the following BEST describes presynaptic facilitation?

A) The modulating neuron enhances neurotransmitter release to the postsynaptic cell.
B) The modulating neuron decreases the effective communication between the cell it is modulating and its postsynaptic cell.
C) The modulating neuron triggers an action potential in the postsynaptic cell.
D) The modulating neuron stabilizes the membrane potential of the postsynaptic cell.
E) The modulating neuron causes an EPSP on the postsynaptic cell.

Question 57

How does temporal summation create an action potential?

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

Question 58

Which of the following is a neurotransmitter that contains a six -carbon ring with two hydroxyl groups and an amine group?

A) acetylcholine
B) norepinephrine
C) nitric oxide
D) neuroactive peptides
E) amino acids

Question 59

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

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

Question 60

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

Question 61

Which of the following neurotransmitters is a catecholamine?

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

Question 62

Which of the following chemicals is NOT a known neurotransmitter?

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

Question 63

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

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

Question 64

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 65

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

Question 66

The action of adrenergic receptors identifies them as

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

Question 67

What chemical targets CB1 receptors?

A) carbonic acid
B) carbon dioxide
C) tetrahydrocannabinol
D) glutamate
E) enkephalin

Question 68

is an amino acid neurotransmitter at excitatory synapses whereas _
Is an amino
Acid neurotransmitter at inhibitory synapses.

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

Question 69

Neuropeptides are synthesized in what region of a neuron?

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

Question 70

Which of the following is a hypothalamic neuropeptide that regulates the sleep -wake cycle?

A) substance P
B) vasopressin
C) melatonin
D) oxytocin
E) orexin

Question 71

Which of the following neurotransmitters is a neuropeptide?

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

Question 72

What two enzymes catalyze the breakdown of catecholamines?

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

Question 73

Histidine, tyrosine, and tryptophan all go on to become what class of neurotransmitters?

A) neuropeptides
B) catecholamines
C) biogenic amines
D) amino acid transmitters
E) purines

Question 74

Which of the following compounds is NOT a neuropeptide?

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

Question 75

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

A) GABA_A only
B) GABA_B only
C) GABA_C only
D) both GABA_A and GABA_B
E) both GABA_A and GABA_C

Question 76

Nitric oxide is a(n)

A) gas
B) amino acid
C) catecholamine
D) neuroactive peptide
E) biogenic amine

Question 77

Which of the following is a biogenic amine that is NOT classified as a catecholamine?

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

Question 78

What is the most common inhibitory neurotransmitter in the central nervous system?

A) GABA
B) aspartate
C) glutamate
D) acetylcholine
E) glycine

Question 79

Which of the following neurotransmitters is a biogenic amine, but not a catecholamine?

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

Question 80

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