Practice Questions - Week 4 Flashcards
Which of the following Nobel laureates was the champion of electrical communication in the nervous system?
Henry Dale
John Dale
Otto Eccles
Otto Loewi
John Eccles
John Eccles
Which of the following events occurs as a consequence of acetylcholine binding to its nicotinic receptor?
- a non-selective cation channel opens
- potassium ions flow out of the cell
- sodium ions flow into the cell
1, 2 & 3
2 only
1 only
3 only
1 & 2 only
2 only
Which of the following is NOT an effect mediated by second messengers that are upregulated by activation of metobotropic receptors in postsynaptic neurones?
a. regulation of gene transcription
b. enzyme activation
c. modification of the sensitivity of ionotropic receptors
d. rapid depolarisation
e. ion channel opening
Rapid depolarisation
Which of the following statements about electrical synapses is/are TRUE?
- rectifying synapses can only pass information in one direction
- bi-directional (reciprocal) synapses have a significant synaptic delay because of the resistance of the gap junctions
- electrical synapses are found in the human retina
1 & 3 only
Which of the following best describes the contribution that Otto Loewi made to science?
Albert Einstein used to listen to Loewi’s music whilst developing the theory of relativity
He discovered that acetylcholine was a neurotransmitter
He discovered cocaine
He developed a complex set of mathematical equations that could be used to model neurones
He discovered connexons
He discovered that acetylcholine was a neurotransmitter
Which of the following is/are an effect mediated by second messengers that are upregulated by activation of metabotropic receptors in postsynaptic neurones?
- rapid depolarisation.
- enzyme activation.
- regulation of gene transcription.
2 & 3 only
Which of the following statements about chemical neurotransmission is FALSE?
Inhibitory synapses are associated with hyperpolarisation of the postsynaptic neurone
there is a delay of approximately 0.5 ms between the action potential arriving in the presynaptic neurone and any noticeable effects in the postsynaptic neurone
neurotransmitters are either excitatory or inhibitory
the movements of ions can induce potential differences
excitatory synapses are associated with depolarisation of the postsynaptic neurone
neurotransmitters are either excitatory or inhibitory
Which of the following neurotransmitters is NOT a biogenic amine?
dopamine
histamine
adrenaline
serotonin
noradrenaline
histamine
When the presynaptic neurone makes a functional contact with the cell body of the postsynaptic neurones this is referred to as?
an axoaxonic synapse
a neuroeffector junction
an axosomatic synapse
an axodendritic synapse
a neuromuscular junction
an axosomatic synapse
Inhibitory postsynaptic potentials are characterised by hyperpolarisation produced by which of the following events?
sodium AND potassium flowing into the cell
potassium flowing into the cell
chloride ions flowing into the cell
chloride ions flowing out of the cell
sodium flowing into the cell
chloride ions flowing into the cell
Large-diameter, dense cored vesicles found in the axon terminal of the presynaptic neurone of a chemical synapse might contain which of the following substances?
Group of answer choices
dopamine
noraderenaline
substance P
adenosine triphosphate
acetylcholine
substance P
Exocytosis of neurotransmitter is a direct consequence of which of the following events?
Group of answer choices
opening of ligand-gated calcium channels
opening of voltage-gated non-selective cation channels
opening of ligand-gated non-selective cation channels
opening of ligand-gated potassium channels
opening of voltage-gated calcium channels
opening of voltage-gated calcium channels
What would be the effect of inhibiting the enzymes that are responsible for degradation of a neurotransmitter at an excitatory synapse?
Group of answer choices
there would be no effect
the concentration of the neurotransmitter in the synaptic cleft would increase
the amount of neurotransmitter released would increase
the amount of neurotransmitter released would decrease
the concentration of the neurotransmitter in the synaptic cleft would decrease
the concentration of the neurotransmitter in the synaptic cleft would increase
Which of the following is NOT a feature of electrical synapses?
Group of answer choices
hemi-channels forming water-filled pores
gap-junctions with a finite resistance
connexons made of connexion
synaptic cleft of only 30 nm
electrical coupling of neurones
synaptic cleft of only 30 nm
(because that’s the cleft width of chemical synapses and electrical is about 3nm)
