WorksheetsiRAT Neuro week 1
Total questions: 6
Worksheet time: 3mins
Name
Class
Date
1.
A 25-year-old male presents with recurrent seizures. EEG shows hyperexcitable neuronal activity. A mutation affects voltage-gated sodium channels.
Which of the following best explains how this mutation alters action potential propagation?
a)
Increased potassium efflux accelerates repolarization, suppressing excitability
b)
Enhanced calcium influx strengthens neurotransmitter release, inhibiting repetitive firing
c)
Reduced chloride influx hyperpolarizes the membrane, preventing abnormal firing
d)
Failure of sodium channel inactivation prolongs depolarization, increasing excitability
e)
Inhibition of sodium–potassium ATPase reduces resting membrane potential
2.
A patient with depression is treated with a selective serotonin reuptake inhibitor (SSRI).
What is the primary mechanism by which this drug enhances synaptic transmission?
a)
Direct agonism of serotonin receptors, mimicking endogenous serotonin
b)
Inhibition of monoamine oxidase, preventing serotonin degradation
c)
Increased vesicular packaging of serotonin, amplifying postsynaptic stimulation
d)
Blockade of presynaptic calcium channels, reducing neurotransmitter release
e)
Inhibition of presynaptic serotonin reuptake, increasing neurotransmitter availability
3.
A patient with syringomyelia presents with bilateral loss of pain and temperature sensation in the upper limbs, but preserved vibration and proprioception.
Which pathway is most affected?
a)
Corticospinal tract
b)
Trigeminothalamic tract
c)
Spinothalamic tract
d)
Vestibular pathway
e)
Dorsal column–medial lemniscus pathway
4.
A 32-year-old woman presents with fatigable muscle weakness. Tests show autoantibodies against postsynaptic receptors.
Which receptor is most likely targeted?
a)
GABA-A receptor
b)
AMPA receptor
c)
Nicotinic acetylcholine receptor
d)
Muscarinic acetylcholine receptor
e)
NMDA receptor
5.
A patient is given benzodiazepines for acute anxiety.
Which mechanism best explains their action?
a)
Inhibit serotonin reuptake, enhancing postsynaptic activity
b)
Decrease potassium conductance, prolonging depolarization
c)
Stimulate NMDA receptors, prolonging EPSPs
d)
Block glutamate release at presynaptic terminals
e)
Increase frequency of chloride channel opening at GABA-A receptors
6.
A 70-year-old male presents with resting tremor and bradykinesia. Imaging shows degeneration of substantia nigra neurons.
Which pathway is primarily affected?
a)
Mesolimbic pathway
b)
Corticospinal tract
c)
Nigrostriatal pathway
d)
Spinocerebellar tract
e)
Dorsal column–medial lemniscus pathway
100 %
