MODULE 3 QUIZ

Question 1

presynaptic and postsynaptic neurons that form ____ synapses are connected via ____

-chemical, connexons
-electrical, the synaptic cleft
-electrical, gap junctions
-chemical, gap junctions

Answer 1

electrical, gap junctions

Question 2

what is the action of the neurotransmitter at a chemical synapse?

-it depolarizes the postsynaptic membrane by delivering an electrical charge
-it acts on receptors in the postsynaptic membrane
-it transfers an AP from the presynaptic neuron to the postsynaptic neuron
-it activates the presynaptic neuron

Answer 2

it acts on receptors in the postsynaptic membrane

Question 3

which characteristics are accepted criterion for classifying a molecule as a neurotransmitter?

-it must be released in response to presynaptic electrical activity
-it must exert an effect on the postsynaptic cell
-it must be present in the presynaptic terminal

Answer 3

all

Question 4

in the sequence of events in neurotransmission at a chemical synapse, which event occurs just after the AP arrives at the presynaptic terminal?

-delivery of the neurotransmitter to the presynaptic terminal
-release of the neurotransmitter
-fusion of the synaptic vesicles with the presynaptic membrane
-influx of Ca2+ into the presynaptic terminal

Answer 4

influx of Ca2+ into the presynaptic terminal

Question 5

at which point during signal transmission at a chemical synapse is exocytosis occurring?

-while Ca2+ enters the presynaptic terminal
-during neurotransmitter release into the synaptic cleft
-as voltage-gated Ca2+ channels are opening
-as neurotransmitter binds to its receptors

Answer 5

during neurotransmitter release into the synaptic cleft

Question 6

true/false: a rise in presynaptic Ca2+ is necessary and sufficient for neurotransmitter release

Answer 6

true

Question 7

miniature end plate potentials, or MEPPs, are produced

-by the smallest neurotransmitters
-by spontaneous release of neurotransmitter
-by the smallest axons
-in response to weak stimuli
-at miniature end plates

Answer 7

by spontaneous release of neurotransmitter

Question 8

if the ____ for postsynaptic potentials is more positive than the ____, the effect of a transmitter is excitatory, and it generates EPSPs

-AP threshold, reversal potential
-AP threshold, resting potential
-resting potential, AP threshold
-reversal potential, resting potential
-reversal potential, AP threshold

Answer 8

reversal potential, AP threshold

Question 9

which statement(s) about EPSPs in the central nervous system is/are true?

-EPSPs are much larger than end plate potentials
-activation of 2 excitatory synapses at about the same time causes the 2 EPSPs to sum together
-an IPSP can sum with suprathreshold EPSPs to prevent the postsynaptic neuron from reaching threshold

Answer 9

-activation of 2 excitatory synapses at about the same time causes the 2 EPSPs to sum together
-an IPSP can sum with suprathreshold EPSPs to prevent the postsynaptic neuron from reaching threshold

Question 10

what is the main cause of myasthenia gravis symptoms?

-autoimmune reaction against acetylcholine receptors
-excessive activity of acetylcholinesterase
-impaired vesicle fusion

Answer 10

autoimmune reaction against acetylcholine receptors