HCS 215 Chapter 8 Test Bank

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

A) ions moving across the synaptic cleft.

B) the diffusion of neurotransmitters.

C) gap junctions.

D) active transport across the synaptic cleft.

E) passive transport across the synaptic cleft.

C

2) Which of the following statements about synapses is FALSE?

A) Communication across electrical synapses is bi-directional.

B) Neurotransmitters can move from one cell to another through gap junctions at an electrical synapse.

C) Communication at chemical synapses is slower than at electrical synapses.

D) Electrical synapses can be gated.

E) Most synapses in the nervous system are chemical synapses.

B

3) Which of the following statements about electrical synapses is FALSE?

A) Gap junctions are formed from proteins called connexins.

B) Electrical synapses connect hypothalamic neurons that release tropic hormones.

C) Electrical synapses are found in the retina.

D) Electrical synapses are found in the brainstem.

E) Electrical synapses are usually for small-response, single neuron firing.

E

4) 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) presynaptic : postsynaptic

B) postsynaptic : presynaptic

C) parasynaptic : postsynaptic

D) presynaptic : parasynaptic

E) terminal : presynaptic

A

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

A) axodendritic

B) axoaxonic

C) axosomatic

D) dendroaxonic

E) somatoaxonic

B

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

A) axodendritic

B) axoaxonic

C) axosomatic

D) dendroaxonic

E) somatoaxonic

C

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

A) axon hillock

B) dendrite

C) cell body

D) axon

E) synaptic cleft

E

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

A) receptor-gated

B) mechanically-gated

C) ligand-gated

D) voltage-gated

E) chemically-gated

D

9) Synaptic vesicles store

A) calcium.

B) sodium.

C) potassium.

D) neurotransmitter.

E) enzymes that degrade neurotransmitter.

D

10) Most neurotransmitters are synthesized in what region of a neuron?

A) cytosol of the axon terminal

B) synaptic vesicles

C) Golgi apparatus

D) rough endoplasmic reticulum

E) axon hillock

A

11) Neurotransmitter release occurs by what mechanism?

A) diffusion

B) primary active transport

C) secondary active transport

D) endocytosis

E) exocytosis

E

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

A) initiation of an action potential in the axon hillock

B) arrival of an action potential at the axon terminal

C) neurotransmitter binding to receptor

D) summation of graded potentials at the axon hillock

E) paracrines released from the post-synaptic cell

B

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

A) initiation of an action potential

B) termination of an action potential

C) fusion of vesicles to the membrane and of exocytosis neurotransmitter

D) diffusion of the neurotransmitter across the membrane and into the cleft

E) movement of calcium through gap junctions

C

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

A) diffusion out of the cleft

B) degradation by enzymes

C) active reuptake across the presynaptic membrane

D) binding to the receptor

E) transport back up the axon to be immediately repackaged

E

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

A) reuptake

B) regeneration

C) recycling

D) resynthesis

E) receptor binding

A

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

A) sodium

B) calcium

C) the distance of the cleft

D) the concentration of neurotransmitter

E) neurotransmitter vesicles

D

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

A) an action potential to move from axon hillock to axon terminal

B) the synthesis of neurotransmitter

C) packaging of neurotransmitter into synaptic vesicles

D) calcium entry to trigger exocytosis

E) the neurotransmitter to diffuse across the synaptic cleft

D

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

A) mechanotropic

B) metabotropic

C) ionotropic

D) potentiotropic

E) chemotropic

C

19) 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) nerve cell stimulated.

C) organ system activated.

D) affinity of the receptor.

E) half-life of the messenger.

A

20) 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 gating of the ion channel by G protein

B) the rapid G protein response that indirectly links receptor to channel

C) the G protein amplification that causes the rapid channel response

D) the presence of that protein functioning as both an ionotropic receptor and as the ion channel

E) the large ion gradient across the membrane

D

21) 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

D

22) 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) neurotransmitter binding to a receptor opens or closes channels that are a separate protein from the receptor.

E) ion binding to a receptor opens channels in the plasma membrane.

A

23) Presynaptic modulation occurs at what type of synapse?

A) axodendritic

B) axoaxonic

C) axosomatic

D) dendrodendritic

E) dendrosomatic

B

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

A) Their gating is linked to a G protein.

B) The channels are slower to open.

C) Intracellular calcium must increase before those channels will open.

D) Ion channels linked to metabotropic receptors must move to the membrane before gating.

E) Metabolic byproducts are required to open those channels.

A

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

A) excitatory postsynaptic potential

B) inhibitory postsynaptic potential

C) suprathreshold postsynaptic potential

D) hyperpolarizing postsynaptic potential

E) inhibitory presynaptic potential

A

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

A) opening of sodium-selective channels

B) opening of potassium-selective channels

C) closing of sodium-selective channels

D) closing of potassium-selective channels

E) opening of channels that permit both sodium and potassium to flow through

E

27) What ion directly triggers neurotransmitter release from the presynaptic neuron?

A) sodium

B) potassium

C) chloride

D) calcium

E) magnesium

D

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

A) phosphodiesterase

B) protein kinase A

C) G protein

D) adenylate cyclase

E) protein kinase C

D

29) 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) phosphodiesterase

B) protein kinase A

C) G protein

D) adenylate cyclase

E) protein kinase C

A

30) Fast excitatory responses not only occur quickly, but they

A) also have a slow component.

B) remain active for a long period of time.

C) end quickly.

D) always create a substantial depolarization.

E) are maintained for minutes to hours.

C

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

A) opening : chloride

B) closure : potassium

C) opening : sodium

D) closure : chloride

E) opening : calcium

A

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

A) opening : potassium

B) closure : potassium

C) opening : sodium

D) closing : chloride

E) opening : calcium

A

33) 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 out of the cell

B) net movement of chloride into the cell

C) movement of chloride equally in both directions

D) absence of any chloride movement

E) depolarization of the cell

A

34) 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 out of the cell

B) net movement of chloride into the cell

C) movement of chloride equally in both directions

D) absence of any chloride movement

E) depolarization of the cell

B

35) 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.

D

36) 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) hyperpolarize

B) depolarize

C) stabilize

D) modify

E) alter

C

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

A) stimulate

B) inhibit

C) facilitate

D) further

E) enhance

B

38) Convergence in neurophysiology refers to which of the following?

A) the presence of EPSPs and IPSPs on a neuron at the same time

B) the communication of several neurons to one postsynaptic cell

C) the summation of graded potentials to determine whether or not an action potential will be generated

D) the level of depolarization required to generate an action potential

E) the arrival of an action potential at the axon terminal

B

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

A) dendrites

B) cell body

C) axon

D) axon hillock

E) rough endoplasmic reticulum

D

40) Divergence in neurophysiology refers to which of the following?

A) the communication of one neuron to several postsynaptic cells

B) the presence of EPSPs and IPSPs on a neuron at the same time

C) the summation of graded potentials to determine whether or not an action potential will be generated

D) the level of depolarization required to generate an action potential

E) the arrival of an action potential at the axon terminal

B

41) For ionotropic receptors, their ________ response ________ the likelihood that two pulses from the same neuron will summate.

A) rapid : decreases

B) rapid : increases

C) rapid : does not affect

D) slow : decreases

E) slow : increases

A

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

A) presynaptic inhibition at an excitatory synapse

B) presynaptic excitation at an excitatory synapse

C) opening of potassium channels on the postsynaptic cell

D) opening of chloride channels on a postsynaptic cell with no active transport of chloride ions

E) opening of chloride channels on a postsynaptic cell that actively transports chloride ions out of the cell

B

43) Which of the following statements about inhibitory synapses is FALSE?

A) Opening of potassium channels can generate an IPSP.

B) Opening of chloride channels can generate an IPSP.

C) In presynaptic inhibition, the lower level potential generated interferes with the oncoming action potential.

D) The membrane potential of the postsynaptic cell can be hyperpolarized.

E) The postsynaptic cell is less likely to generate an action potential.

C

44) How does temporal summation create an action potential?

A) Two or more postsynaptic potentials are generated in rapid succession at the same synapse before they can dissipate, thereby exceeding threshold.

B) Generator potentials are at the same tempo on adjacent neurons.

C) Potentials are generated on several dendrites at the same time to trigger threshold and the production of an action potential.

D) It is frequency modulated and of the same amplitude for intensity.

E) The temporal lobe in the brain stimulates EPSPs to trigger an action potential.

A

45) 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) decrease : amplitude

C) increase : frequency

D) increase : amplitude

E) not be altered : amplitude

A

46) Suprathreshold graded potentials within a neuron can generate ________ action potential(s) at the axon hillock, which allows for the ________ of the magnitude of the stimulus.

A) multiple : amplitude coding

B) multiple : frequency coding

C) a single : frequency coding

D) a single : amplitude coding

E) several : amplitude coding

B

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

A) inhibiting

B) decreasing

C) increasing

D) modulating

E) enhancing

D

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

A) membrane potential

B) calcium influx

C) the vesicles selected for release

D) sodium channels

E) potassium channels

B

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

A) an increase in neurotransmitter release from the neuron it is modulating

B) a hyperpolarization of the neuron it is modulating

C) an IPSP on the postsynaptic cell

D) an EPSP on the postsynaptic cell

E) a decrease in calcium entry into the axon terminal of the neuron it is modulating

E

50) Which of the following BEST describes presynaptic facilitation?

A) The modulating neuron causes an EPSP on the postsynaptic cell.

B) The modulating neuron enhances neurotransmitter release to the 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 decreases the effective communication between the cell it is modulating and its postsynaptic cell.

B

51) 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 : acetyl CoA + choline

B) choline acetyl transferase : choline + acetate

C) acetylcholinesterase : choline

D) choline acetyl transferase : acetyl CoA + choline

E) choline acetyl transferase : acetyl CoA

B

52) Neurons that synthesize and release acetylcholine are called ________ neurons.

A) ACTH

B) gamma

C) adrenergic

D) dopaminergic

E) cholinergic

E

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

A) acetate + choline

B) methylcholine + acetate

C) acetyl CoA + choline

D) acetate only

E) choline only

A

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

A) acetylcholine

B) acetyl CoA

C) acetate

D) choline

E) epinephrine

D

55) What type of receptor is both ionotropic and cholinergic?

A) muscarinic

B) dopaminergic

C) serotonergic

D) adrenergic

E) nicotinic

E

56) What type of receptor is both metabotropic and cholinergic?

A) muscarinic

B) dopaminergic

C) serotonergic

D) adrenergic

E) nicotinic

A

57) 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) amino acids

D) neuroactive peptides

E) nitric oxide

B

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

A) adenosine : amino acid

B) norepinephrine : catecholamine

C) histamine : biogenic amine

D) enkephalin : neuropeptide

E) nitric oxide : gas

A

59) 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) There are different message transduction systems.

B) Each tissue is different, so no two can have the same effect.

C) All of the effects are a result of membrane dehydration.

D) Histamine recombines with other endogenous substances once inside the target cell.

E) They are dependent on which cell secretes the histamine.

A

60) Biogenic amines are synthesized in what region of a neuron?

A) cytosol of the cell body

B) axon hillock

C) rough endoplasmic reticulum

D) extracellular space

E) cytosol of the axon terminal

E

61) The action of adrenergic receptors identifies them as ________ receptors.

A) metabotropic

B) chemotropic

C) ionotropic

D) voltage-gated

E) mechanically-gated

A

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

A) norepinephrine

B) epinephrine

C) adrenaline

D) serotonin

E) dopamine

D

63) What two enzymes catalyze the breakdown of catecholamines?

A) catechol-O-methyltransferase and acetylcholinesterase

B) acetylcholinesterase and dopa decarboxylase

C) monoamine oxidase and phenylethanolamine N methyltransferase

D) dopa decarboxylase and phenylethanolamine N methyltransferase

E) monoamine oxidase and catechol-O-methyltransferase

E

64) 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

E

65) 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

D

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

A) biogenic amines

B) amino acid transmitters

C) neuropeptides

D) purines

E) catecholamines

A

67) ________ is an amino acid neurotransmitter at excitatory synapses whereas ________ is an amino acid neurotransmitter at inhibitory synapses.

A) Gamma-aminobutyric acid : glutamate

B) Gamma-aminobutyric acid : glycine

C) Glycine : aspartate

D) Aspartate : glycine

E) Glutamate : aspartate

D

68) 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

A

69) Why are amino acid neurotransmitters NOT considered biogenic amines?

A) Biogenic amines still contain an amine group, but are no longer amino acids.

B) Amino acids are excitatory only, while biogenic amines are not.

C) Amino acids used to make biogenic amines are not used for anything else.

D) Biogenic amines may be taken up by non-conducting cells, while amino acids are not.

E) Amino acids lose their activity when stored, while biogenic amines do not.

A

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

A) glycine

B) GABA

C) glutamate

D) acetylcholine

E) aspartate

B

71) Neuropeptides are synthesized in what region of a neuron?

A) within the axon terminal

B) in the rough endoplasmic reticulum

C) along the axon

D) within the vesicles

E) at the dendrite

B

72) Which of the following compounds is NOT a neuropeptide?

A) substance P

B) vasopressin

C) oxytocin

D) endorphin

E) epinephrine

E

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

A) orexin

B) vasopressin

C) oxytocin

D) melatonin

E) substance P

A

74) Nitric oxide is a(n) ________ that functions as a neurotransmitter.

A) catecholamine

B) gas

C) neuroactive peptide

D) biogenic amine

E) amino acid

B

75) Which of the following chemicals is NOT a known neurotransmitter?

A) acetylcholine

B) nitric oxide

C) ATP

D) substance P

E) carbon dioxide

E

76) What chemical targets CB1 receptors?

A) tetrahydrocannabinol

B) enkephalin

C) glutamate

D) carbonic acid

E) carbon dioxide

A

77) Which of the following neurotransmitters is a neuropeptide?

A) acetylcholine

B) glycine

C) substance P

D) norepinephrine

E) aspartate

C

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

A) glycine

B) aspartate

C) acetylcholine

D) substance P

E) norepinephrine

B

79) Which of the following neurotransmitters is a catecholamine?

A) substance P

B) norepinephrine

C) acetylcholine

D) aspartate

E) glycine

B

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

A) acetylcholine

B) serotonin

C) aspartate

D) substance P

E) norepinephrine

B

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

A) substance P

B) aspartate

C) norepinephrine

D) acetylcholine

E) glycine

E

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

A) substance P

B) norepinephrine

C) glycine

D) acetylcholine

E) aspartate

D

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

A) membrane stabilization

B) hyperpolarization

C) returns to -70 mV

D) depolarization

E) repolarization

D

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

A) membrane stabilization

B) repolarization

C) hyperpolarization

D) returns to -70 mV

E) depolarization

C

85) What happens to the resting membrane potential of -70 mV when potassium channels open?

A) repolarization

B) returns to -70 mV

C) membrane stabilization

D) hyperpolarization

E) depolarization

D

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

A) repolarization

B) hyperpolarization

C) depolarization

D) returns to -70 mV

E) membrane stabilization

C

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

A) hyperpolarization

B) depolarization

C) membrane stabilization

D) returns to -70 mV

E) repolarization

A

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

A) repolarization

B) hyperpolarization

C) depolarization

D) returns to -70 mV

E) membrane stabilization

B

89) 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) repolarization

C) hyperpolarization

D) membrane stabilization

E) depolarization

E

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

A) hyperpolarization

B) repolarization

C) membrane stabilization

D) depolarization

E) returns to -70 mV

D

91) Which enzyme catalyzes the synthesis of cAMP?

A) monoamine oxidase

B) adenylate cyclase

C) acetylcholinesterase

D) catechol-O-methyltransferase

E) choline acetyl transferase

B

92) Which enzyme catalyzes the synthesis of acetylcholine?

A) monoamine oxidase

B) adenylate cyclase

C) acetylcholinesterase

D) choline acetyl transferase

E) catechol-O-methyltransferase

B

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

A) choline acetyl transferase

B) adenylate cyclase

C) monoamine oxidase

D) catechol-O-methyltransferase

E) acetylcholinesterase

C

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

A) monoamine oxidase

B) adenylate cyclase

C) catechol-O-methyltransferase

D) acetylcholinesterase

E) choline acetyl transferase

C

95) What enzyme catalyzes breakdown of acetylcholine?

A) catechol-O-methyltransferase

B) adenylate cyclase

C) choline acetyl transferase

D) monoamine oxidase

E) acetylcholinesterase

E

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

A) alpha adrenergic.

B) nicotinic cholinergic.

C) beta adrenergic.

D) NMDA

E) muscarinic cholinergic.

B

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

A) GABAA

B) kainate glutamatergic.

C) nicotinic cholinergic.

D) AMPA glutamatergic.

E) muscarinic cholinergic.

E

106) What channels are the most abundant type of voltage-gated channel within the axon terminal and are responsible for the release of neurotransmitter?

A) voltage-gated calcium channels

B) voltage-gated adrenergic channels

C) voltage-gated sodium channels

D) voltage-gated cholinergic channels

E) voltage-gated potassium channels

A

107) If a membrane is depolarized to +10 mV, which cation will move more frequently through a small cation channel?

A) hydrogen

B) calcium

C) magnesium

D) potassium

E) sodium

D

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

A) sodium

B) potassium

C) magnesium

D) calcium

E) hydrogen

A