NU 578
NU 578 Unit 3 Exam| Questions and Answers
|with Detailed Rationales| 2026 Graded A+
1.
Which receptor mediates bronchodilation in the “fight or flight” response?
A. Alpha-1
B. Beta-1
C. Beta-2
D. Muscarinic
Rationale:
Beta-2 adrenergic receptors are primarily located in the smooth muscle of the bronchi and certain
vascular beds. When stimulated (e.g., by epinephrine), they cause relaxation of bronchial smooth
muscle, resulting in bronchodilation. This allows increased airflow to the lungs during stress
(“fight or flight”). Alpha-1 receptors instead cause vasoconstriction, and beta-1 receptors
primarily affect the heart by increasing rate and contractility.
2.
A patient taking an anticholinergic reports dry mouth and urinary retention. This is due to
blockade of:
A. Nicotinic receptors
B. Muscarinic receptors
C. Alpha receptors
D. Beta receptors
Rationale:
Anticholinergic medications inhibit the action of acetylcholine at muscarinic receptors, which are
part of the parasympathetic nervous system. Blocking these receptors reduces glandular
secretions (causing dry mouth), decreases bladder contraction (leading to urinary retention), and
may also cause blurred vision and constipation. Nicotinic receptors are mainly found at
neuromuscular junctions and autonomic ganglia, not responsible for these symptoms.
3.
Which drug is a selective beta-1 blocker?
A. Propranolol
B. Metoprolol
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C. Labetalol
D. Carvedilol
Rationale:
Metoprolol is a cardioselective beta-1 blocker, meaning it primarily targets beta-1 receptors in
the heart. This reduces heart rate, myocardial contractility, and cardiac output. Propranolol is
non-selective (blocks both beta-1 and beta-2), while labetalol and carvedilol block both alpha
and beta receptors.
4.
Stimulation of alpha-1 receptors causes:
A. Vasodilation
B. Vasoconstriction
C. Bronchodilation
D. Decreased BP
Rationale:
Alpha-1 receptors are located on vascular smooth muscle. When activated, they cause
vasoconstriction, which increases systemic vascular resistance and raises blood pressure. This
mechanism is important in maintaining perfusion during stress but can contribute to hypertension
if overactive.
5.
Which drug class reduces heart rate and contractility?
A. ACE inhibitors
B. Beta-blockers
C. Diuretics
D. ARBs
Rationale:
Beta-blockers inhibit beta-1 receptors in the heart, leading to decreased heart rate (negative
chronotropic effect) and decreased contractility (negative inotropic effect). This reduces
myocardial oxygen demand and is beneficial in conditions like hypertension, angina, and heart
failure.
6.
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, NU 578
ACE inhibitors reduce blood pressure by:
A. Increasing renin
B. Blocking angiotensin II formation
C. Increasing sodium retention
D. Stimulating aldosterone
Rationale:
ACE inhibitors block the angiotensin-converting enzyme, preventing the conversion of
angiotensin I to angiotensin II. Since angiotensin II is a potent vasoconstrictor and stimulates
aldosterone release, blocking it leads to vasodilation and decreased sodium and water retention,
thereby lowering blood pressure.
7.
A persistent dry cough is associated with:
A. ARBs
B. ACE inhibitors
C. Beta-blockers
D. Diuretics
Rationale:
ACE inhibitors increase levels of bradykinin because ACE normally breaks it down. Elevated
bradykinin levels irritate the respiratory tract, leading to a dry, persistent cough. This is a
common reason patients are switched to ARBs.
8.
Which medication is preferred if a patient cannot tolerate ACE inhibitors?
A. Beta-blocker
B. ARB (Losartan)
C. Diuretic
D. Calcium channel blocker
Rationale:
Angiotensin receptor blockers (ARBs) directly block angiotensin II receptors without affecting
bradykinin levels. Therefore, they provide similar cardiovascular and renal benefits as ACE
inhibitors but without the side effect of cough.
9.
NU 578
NU 578 Unit 3 Exam| Questions and Answers
|with Detailed Rationales| 2026 Graded A+
1.
Which receptor mediates bronchodilation in the “fight or flight” response?
A. Alpha-1
B. Beta-1
C. Beta-2
D. Muscarinic
Rationale:
Beta-2 adrenergic receptors are primarily located in the smooth muscle of the bronchi and certain
vascular beds. When stimulated (e.g., by epinephrine), they cause relaxation of bronchial smooth
muscle, resulting in bronchodilation. This allows increased airflow to the lungs during stress
(“fight or flight”). Alpha-1 receptors instead cause vasoconstriction, and beta-1 receptors
primarily affect the heart by increasing rate and contractility.
2.
A patient taking an anticholinergic reports dry mouth and urinary retention. This is due to
blockade of:
A. Nicotinic receptors
B. Muscarinic receptors
C. Alpha receptors
D. Beta receptors
Rationale:
Anticholinergic medications inhibit the action of acetylcholine at muscarinic receptors, which are
part of the parasympathetic nervous system. Blocking these receptors reduces glandular
secretions (causing dry mouth), decreases bladder contraction (leading to urinary retention), and
may also cause blurred vision and constipation. Nicotinic receptors are mainly found at
neuromuscular junctions and autonomic ganglia, not responsible for these symptoms.
3.
Which drug is a selective beta-1 blocker?
A. Propranolol
B. Metoprolol
NU 578
,NU 578
C. Labetalol
D. Carvedilol
Rationale:
Metoprolol is a cardioselective beta-1 blocker, meaning it primarily targets beta-1 receptors in
the heart. This reduces heart rate, myocardial contractility, and cardiac output. Propranolol is
non-selective (blocks both beta-1 and beta-2), while labetalol and carvedilol block both alpha
and beta receptors.
4.
Stimulation of alpha-1 receptors causes:
A. Vasodilation
B. Vasoconstriction
C. Bronchodilation
D. Decreased BP
Rationale:
Alpha-1 receptors are located on vascular smooth muscle. When activated, they cause
vasoconstriction, which increases systemic vascular resistance and raises blood pressure. This
mechanism is important in maintaining perfusion during stress but can contribute to hypertension
if overactive.
5.
Which drug class reduces heart rate and contractility?
A. ACE inhibitors
B. Beta-blockers
C. Diuretics
D. ARBs
Rationale:
Beta-blockers inhibit beta-1 receptors in the heart, leading to decreased heart rate (negative
chronotropic effect) and decreased contractility (negative inotropic effect). This reduces
myocardial oxygen demand and is beneficial in conditions like hypertension, angina, and heart
failure.
6.
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, NU 578
ACE inhibitors reduce blood pressure by:
A. Increasing renin
B. Blocking angiotensin II formation
C. Increasing sodium retention
D. Stimulating aldosterone
Rationale:
ACE inhibitors block the angiotensin-converting enzyme, preventing the conversion of
angiotensin I to angiotensin II. Since angiotensin II is a potent vasoconstrictor and stimulates
aldosterone release, blocking it leads to vasodilation and decreased sodium and water retention,
thereby lowering blood pressure.
7.
A persistent dry cough is associated with:
A. ARBs
B. ACE inhibitors
C. Beta-blockers
D. Diuretics
Rationale:
ACE inhibitors increase levels of bradykinin because ACE normally breaks it down. Elevated
bradykinin levels irritate the respiratory tract, leading to a dry, persistent cough. This is a
common reason patients are switched to ARBs.
8.
Which medication is preferred if a patient cannot tolerate ACE inhibitors?
A. Beta-blocker
B. ARB (Losartan)
C. Diuretic
D. Calcium channel blocker
Rationale:
Angiotensin receptor blockers (ARBs) directly block angiotensin II receptors without affecting
bradykinin levels. Therefore, they provide similar cardiovascular and renal benefits as ACE
inhibitors but without the side effect of cough.
9.
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