MSN 671 FINAL EXAM 67 QUESTIONS WITH
VERIFIED ANSWERS 2025/2026
Action potential traveling down the presynaptic axon. Upon reaching the terminal
Ca²⁺ enters through voltage-sensitive calcium channels, triggering the exocytosis
of neurotransmitter-filled vesicles into the synaptic cleft. The released
neurotransmitters (e.g., dopamine, serotonin, norepinephrine) then bind to
postsynaptic receptors, initiating a new electrical signal in the receiving neuron. -
CORRECT ANSWER Classic synaptic neurotransmission
open upon neurotransmitter binding to allow rapid ion passage - CORRECT
ANSWER Ligand-gated ion channel
open in response to electrical changes to propagate action potentials. - CORRECT
ANSWER Voltage-sensitive ion channel
type of voltage-sensitive channel essential for depolarization - CORRECT ANSWER
Sodium-charged ion channel
(DAT, SERT, NET) clear neurotransmitters from the cleft to end the signal -
CORRECT ANSWER Presynaptic transporter
Regulates attention and arousal; low levels may result in ADHD/depression, while
high levels can lead to anxiety - CORRECT ANSWER Norepinephrine (NE)
, Crucial for memory and learning; deficiency is linked to Alzheimer's disease,
whereas excess may cause muscle cramps/seizures - CORRECT ANSWER
Acetylcholine
Synthesized in the pineal gland during darkness, it regulates the circadian rhythm
and promotes sleep - CORRECT ANSWER Melatonin
Modulates mood and appetite; its deficiency can cause depression/anxiety, and
excess may trigger serotonin syndrome - CORRECT ANSWER Serotonin
Key for reward and motor control; deficiency is associated with Parkinson's and
depression, while excess is linked to schizophrenia - CORRECT ANSWER Dopamine
Provides inhibitory control to prevent neuronal overexcitation; low levels may lead
to anxiety and seizures, high levels to sedation - CORRECT ANSWER GABA
Maintains wakefulness; overactivity can cause insomnia, and blockade (by some
antipsychotics) results in sedation and weight gain - CORRECT ANSWER Histamine
During darkness, the pineal gland synthesizes melatonin from serotonin using N-
acetyltransferase. Melatonin levels rise at night, signaling sleep onset by acting on
MT1/MT2 receptors to regulate the circadian rhythm - CORRECT ANSWER Process
of melatonin production
Tardive dyskinesia results from chronic blockade of dopamine D2 receptors
(notably by typical antipsychotics like haloperidol). This leads to dopamine
VERIFIED ANSWERS 2025/2026
Action potential traveling down the presynaptic axon. Upon reaching the terminal
Ca²⁺ enters through voltage-sensitive calcium channels, triggering the exocytosis
of neurotransmitter-filled vesicles into the synaptic cleft. The released
neurotransmitters (e.g., dopamine, serotonin, norepinephrine) then bind to
postsynaptic receptors, initiating a new electrical signal in the receiving neuron. -
CORRECT ANSWER Classic synaptic neurotransmission
open upon neurotransmitter binding to allow rapid ion passage - CORRECT
ANSWER Ligand-gated ion channel
open in response to electrical changes to propagate action potentials. - CORRECT
ANSWER Voltage-sensitive ion channel
type of voltage-sensitive channel essential for depolarization - CORRECT ANSWER
Sodium-charged ion channel
(DAT, SERT, NET) clear neurotransmitters from the cleft to end the signal -
CORRECT ANSWER Presynaptic transporter
Regulates attention and arousal; low levels may result in ADHD/depression, while
high levels can lead to anxiety - CORRECT ANSWER Norepinephrine (NE)
, Crucial for memory and learning; deficiency is linked to Alzheimer's disease,
whereas excess may cause muscle cramps/seizures - CORRECT ANSWER
Acetylcholine
Synthesized in the pineal gland during darkness, it regulates the circadian rhythm
and promotes sleep - CORRECT ANSWER Melatonin
Modulates mood and appetite; its deficiency can cause depression/anxiety, and
excess may trigger serotonin syndrome - CORRECT ANSWER Serotonin
Key for reward and motor control; deficiency is associated with Parkinson's and
depression, while excess is linked to schizophrenia - CORRECT ANSWER Dopamine
Provides inhibitory control to prevent neuronal overexcitation; low levels may lead
to anxiety and seizures, high levels to sedation - CORRECT ANSWER GABA
Maintains wakefulness; overactivity can cause insomnia, and blockade (by some
antipsychotics) results in sedation and weight gain - CORRECT ANSWER Histamine
During darkness, the pineal gland synthesizes melatonin from serotonin using N-
acetyltransferase. Melatonin levels rise at night, signaling sleep onset by acting on
MT1/MT2 receptors to regulate the circadian rhythm - CORRECT ANSWER Process
of melatonin production
Tardive dyskinesia results from chronic blockade of dopamine D2 receptors
(notably by typical antipsychotics like haloperidol). This leads to dopamine
