NR546 PSYCHOPHARMACOLOGY FOR PMHNP
MIDTERM EXAM 2026/2027 | Chamberlain University
| Questions & Verified Answers | Pass Guaranteed -
A+ Graded
Section 1: Neurotransmission & Receptor Pharmacology (Q1-12)
Q1. A PMHNP is reviewing neurotransmitter synthesis for a patient starting sertraline.
Serotonin (5-HT) is synthesized from which amino acid precursor through
hydroxylation and decarboxylation?
A. Tyrosine
B. Tryptophan
C. Phenylalanine
D. Glutamate
Rationale: Serotonin is synthesized from the essential amino acid tryptophan via
tryptophan hydroxylase (rate-limiting step) and aromatic L-amino acid
decarboxylase. Tyrosine is the precursor for dopamine and norepinephrine,
phenylalanine converts to tyrosine, and glutamate is an excitatory neurotransmitter
itself.
Correct Answer: B
Q2. A patient asks why their antidepressant takes 4-6 weeks to work despite
immediate receptor blockade. The PMHNP explains that delayed therapeutic effects
are related to:
A. Immediate depletion of neurotransmitter stores
B. Downregulation of presynaptic autoreceptors and enhanced postsynaptic
signaling with neuroplasticity changes
C. Instantaneous G-protein activation
D. Direct ion channel opening
,2
Rationale: Antidepressant efficacy requires weeks because initial reuptake inhibition
increases synaptic monoamine levels, but presynaptic autoreceptor desensitization
and downstream neuroplasticity (BDNF, receptor adaptation) are necessary for
clinical improvement. This explains the therapeutic lag to patients.
Correct Answer: B
Q3. Dopamine is metabolized by which two primary enzymes, and which metabolite
is measured in CSF and urine as an index of central dopaminergic activity?
A. COMT and MAO; homovanillic acid (HVA)
B. Acetylcholinesterase and butyrylcholinesterase; acetylcholine
C. CYP2D6 and CYP3A4; 5-HIAA
D. DOPA decarboxylase and tyrosine hydroxylase; dopamine
Rationale: Dopamine is metabolized by catechol-O-methyltransferase (COMT) and
monoamine oxidase (MAO) to homovanillic acid (HVA), the primary measurable
metabolite. 5-HIAA is a serotonin metabolite, and the other enzymes listed are
involved in synthesis rather than degradation.
Correct Answer: A
Q4. GABA-A receptors are classified as which type of receptor, and benzodiazepines
exert their anxiolytic effect through which specific mechanism?
A. Metabotropic; G-protein coupled second messenger activation
B. Ionotropic; positive allosteric modulation increasing chloride ion influx
C. Tyrosine kinase-linked; gene transcription activation
D. Nuclear receptor; DNA binding
Rationale: GABA-A receptors are ligand-gated ion channels (ionotropic).
Benzodiazepines bind to an allosteric site, increasing the frequency of chloride
channel opening when GABA is present, hyperpolarizing neurons and reducing
excitability. This is distinct from metabotropic GABA-B receptors.
,3
Correct Answer: B
Q5. A PMHNP is explaining the mechanism of aripiprazole to a patient. Aripiprazole
is best described as a:
A. Full D2 receptor agonist
B. D2 receptor antagonist with high affinity
C. D2 partial agonist and 5-HT1A partial agonist with 5-HT2A antagonism
D. Pure 5-HT2A inverse agonist
Rationale: Aripiprazole is a D2 partial agonist (intrinsic activity ~30%), 5-HT1A partial
agonist, and 5-HT2A antagonist. This "dopamine system stabilizer" profile reduces
EPS and prolactin elevation while maintaining antipsychotic efficacy. It is not a full
agonist, pure antagonist, or inverse agonist.
Correct Answer: C
Q6. Glutamate acts on NMDA receptors, which require both glutamate binding and
which co-agonist for channel opening, making this receptor unique among
ionotropic glutamate receptors?
A. GABA
B. Glycine (or D-serine)
C. Acetylcholine
D. Serotonin
Rationale: NMDA receptors are unique among ionotropic glutamate receptors
because they require dual activation: glutamate binds to the primary site, and glycine
(or D-serine) binds to a co-agonist site, both necessary for channel opening and
calcium influx. This has implications for memantine and ketamine pharmacology.
Correct Answer: B
, 4
Q7. Norepinephrine is released from presynaptic terminals and acts on postsynaptic
alpha-1 adrenergic receptors. The signal transduction mechanism for alpha-1
receptors involves:
A. Gs protein stimulating adenylyl cyclase and increasing cAMP
B. Gq protein activating phospholipase C, increasing IP3 and DAG
C. Gi protein inhibiting adenylyl cyclase and decreasing cAMP
D. Direct ligand-gated ion channel opening
Rationale: Alpha-1 adrenergic receptors couple to Gq proteins, activating
phospholipase C to produce IP3 (calcium mobilization) and DAG (PKC activation). Gs
couples beta-adrenergic receptors, Gi couples alpha-2 receptors, and direct ion
channel gating is not the alpha-1 mechanism.
Correct Answer: B
Q8. A patient on clonidine for ADHD experiences rebound hypertension after abrupt
discontinuation. This occurs because clonidine is an alpha-2A agonist that:
A. Stimulates postsynaptic alpha-2 receptors in the vasculature
B. Reduces norepinephrine release presynaptically; abrupt stop causes
norepinephrine surge and vasoconstriction
C. Blocks alpha-1 receptors in the CNS
D. Increases dopamine release in the prefrontal cortex
Rationale: Alpha-2A agonists (clonidine, guanfacine) reduce norepinephrine release
via presynaptic autoreceptor stimulation. Abrupt discontinuation removes this brake,
causing norepinephrine rebound, sympathetic surge, and hypertension. This is not
related to postsynaptic alpha-2 stimulation or alpha-1 blockade.
Correct Answer: B
Q9. Serotonin reuptake from the synaptic cleft is primarily mediated by which
transporter, the target of SSRIs and SNRIs?