BIOL 351 | BIOL351 Module 2: Pharmacology
Updated and Latest Questions and Correct
Answers with Rationale - Portage Learning
1. Which of the following receptors is primarily responsible for increasing heart rate and
contractility when stimulated by an adrenergic agonist?
A. Beta-1
B. Alpha-2
C. Alpha-1
D. Beta-2
Correct Answer: A
Explanation: Beta-1 receptors are predominantly located in the heart and lead to positive
inotropic and chronotropic effects. Stimulating these receptors increases the force of
contraction and the heart rate through the sympathetic nervous system. Alpha-1 receptors
primarily cause vasoconstriction rather than direct cardiac stimulation. Beta-2 receptors
are mostly found in the lungs where they cause bronchodilation. Clinically, drugs like
dobutamine target these Beta-1 receptors to support cardiac output in heart failure.
2. What is the primary mechanism of action for Bethanechol in the treatment of post-
operative urinary retention?
A. Inhibition of acetylcholinesterase
B. Direct stimulation of muscarinic receptors
C. Antagonism of nicotinic receptors
D. Stimulation of Alpha-1 adrenergic receptors
Correct Answer: B
Explanation: Bethanechol is a direct-acting cholinergic agonist that specifically targets
muscarinic receptors. By binding to these receptors in the bladder, it causes the detrusor
muscle to contract and the sphincter to relax. This action facilitates the emptying of the
bladder in patients without mechanical obstructions. Unlike neostigmine, it does not work
by inhibiting the breakdown of acetylcholine. Patients should be monitored for
parasympathetic side effects like bradycardia or excessive salivation during use.
3. A patient with asthma is prescribed Albuterol; which receptor does this drug primarily
activate to induce bronchodilation?
A. Beta-1
B. Beta-2
,C. Alpha-1
D. Muscarinic M3
Correct Answer: B
Explanation: Albuterol is a selective Beta-2 adrenergic agonist that works by relaxing
bronchial smooth muscle. Activation of Beta-2 receptors increases cyclic AMP levels,
leading to rapid bronchodilation during acute asthma attacks. While it is selective, high
doses may occasionally cause some Beta-1 cross-reactivity leading to tachycardia. Alpha-1
receptors are not involved in airway relaxation and instead promote vasoconstriction. This
medication remains a first-line treatment for managing acute symptoms of reversible
airway obstruction.
4. Which clinical effect would a nurse expect to see after the administration of Atropine, a
muscarinic antagonist?
A. Increased salivation
B. Pupillary constriction (Miosis)
C. Decreased heart rate
D. Increased heart rate
Correct Answer: D
Explanation: Atropine works by blocking muscarinic receptors, which prevents the
parasympathetic nervous system from slowing the heart rate. By inhibiting the vagus
nerve’s influence on the SA node, it effectively increases the heart rate in cases of
bradycardia. It also causes systemic effects such as dry mouth and dilated pupils due to
receptor blockade elsewhere. Miosis and increased salivation are cholinergic effects which
are the opposite of what Atropine produces. Understanding these side effects is crucial for
patient safety during pre-operative or emergency use.
5. What is the rationale for using Epinephrine during an anaphylactic reaction?
A. Alpha-1 mediated vasoconstriction and Beta-2 mediated bronchodilation
B. Selective Beta-2 stimulation to lower blood pressure
C. Muscarinic blockade to reduce respiratory secretions
D. Inhibition of norepinephrine release at the synapse
Correct Answer: A
Explanation: Epinephrine is a non-selective adrenergic agonist that acts on Alpha-1, Beta-
1, and Beta-2 receptors. The Alpha-1 stimulation causes vasoconstriction to raise
dangerously low blood pressure during anaphylaxis. Simultaneously, Beta-2 stimulation
relaxes the smooth muscles in the lungs to open the airways. Beta-1 stimulation also
, provides cardiac support by increasing heart rate and contractility. This multi-receptor
approach makes it the gold standard for treating life-threatening allergic reactions.
6. Which drug is a selective Alpha-1 antagonist commonly used to treat hypertension and
benign prostatic hyperplasia (BPH)?
A. Prazosin
B. Clonidine
C. Propranolol
D. Metoprolol
Correct Answer: A
Explanation: Prazosin works by selectively blocking Alpha-1 receptors on vascular smooth
muscle and the bladder neck. This results in vasodilation, which effectively lowers systemic
blood pressure in hypertensive patients. In BPH, the relaxation of the smooth muscle in the
prostate and bladder neck improves urinary flow. Propranolol and Metoprolol are beta-
blockers and do not target the Alpha-1 receptor primarily. Patients should be warned about
the ‘first-dose effect’ which can cause significant orthostatic hypotension.
7. How does Clonidine exert its primary therapeutic effect in the management of
hypertension?
A. Stimulating peripheral Alpha-1 receptors
B. Blocking Beta-1 receptors in the heart
C. Stimulating central Alpha-2 receptors
D. Inhibiting the release of acetylcholine
Correct Answer: C
Explanation: Clonidine acts as a central Alpha-2 adrenergic agonist in the brainstem. By
stimulating these receptors, it reduces the sympathetic outflow from the central nervous
system to the peripheral vasculature. This leads to a decrease in heart rate and peripheral
vascular resistance, lowering blood pressure. It is not an antagonist like Prazosin or a
direct beta-blocker like Propranolol. Sudden discontinuation of Clonidine can cause
dangerous rebound hypertension due to a surge in catecholamines.
8. A patient with Myasthenia Gravis is treated with Neostigmine. What is the mechanism of
this drug?
A. It inhibits the enzyme acetylcholinesterase
B. It directly stimulates nicotinic receptors at the NMJ
C. It blocks muscarinic receptors to prevent tremors
D. It increases the reuptake of choline into the neuron
Updated and Latest Questions and Correct
Answers with Rationale - Portage Learning
1. Which of the following receptors is primarily responsible for increasing heart rate and
contractility when stimulated by an adrenergic agonist?
A. Beta-1
B. Alpha-2
C. Alpha-1
D. Beta-2
Correct Answer: A
Explanation: Beta-1 receptors are predominantly located in the heart and lead to positive
inotropic and chronotropic effects. Stimulating these receptors increases the force of
contraction and the heart rate through the sympathetic nervous system. Alpha-1 receptors
primarily cause vasoconstriction rather than direct cardiac stimulation. Beta-2 receptors
are mostly found in the lungs where they cause bronchodilation. Clinically, drugs like
dobutamine target these Beta-1 receptors to support cardiac output in heart failure.
2. What is the primary mechanism of action for Bethanechol in the treatment of post-
operative urinary retention?
A. Inhibition of acetylcholinesterase
B. Direct stimulation of muscarinic receptors
C. Antagonism of nicotinic receptors
D. Stimulation of Alpha-1 adrenergic receptors
Correct Answer: B
Explanation: Bethanechol is a direct-acting cholinergic agonist that specifically targets
muscarinic receptors. By binding to these receptors in the bladder, it causes the detrusor
muscle to contract and the sphincter to relax. This action facilitates the emptying of the
bladder in patients without mechanical obstructions. Unlike neostigmine, it does not work
by inhibiting the breakdown of acetylcholine. Patients should be monitored for
parasympathetic side effects like bradycardia or excessive salivation during use.
3. A patient with asthma is prescribed Albuterol; which receptor does this drug primarily
activate to induce bronchodilation?
A. Beta-1
B. Beta-2
,C. Alpha-1
D. Muscarinic M3
Correct Answer: B
Explanation: Albuterol is a selective Beta-2 adrenergic agonist that works by relaxing
bronchial smooth muscle. Activation of Beta-2 receptors increases cyclic AMP levels,
leading to rapid bronchodilation during acute asthma attacks. While it is selective, high
doses may occasionally cause some Beta-1 cross-reactivity leading to tachycardia. Alpha-1
receptors are not involved in airway relaxation and instead promote vasoconstriction. This
medication remains a first-line treatment for managing acute symptoms of reversible
airway obstruction.
4. Which clinical effect would a nurse expect to see after the administration of Atropine, a
muscarinic antagonist?
A. Increased salivation
B. Pupillary constriction (Miosis)
C. Decreased heart rate
D. Increased heart rate
Correct Answer: D
Explanation: Atropine works by blocking muscarinic receptors, which prevents the
parasympathetic nervous system from slowing the heart rate. By inhibiting the vagus
nerve’s influence on the SA node, it effectively increases the heart rate in cases of
bradycardia. It also causes systemic effects such as dry mouth and dilated pupils due to
receptor blockade elsewhere. Miosis and increased salivation are cholinergic effects which
are the opposite of what Atropine produces. Understanding these side effects is crucial for
patient safety during pre-operative or emergency use.
5. What is the rationale for using Epinephrine during an anaphylactic reaction?
A. Alpha-1 mediated vasoconstriction and Beta-2 mediated bronchodilation
B. Selective Beta-2 stimulation to lower blood pressure
C. Muscarinic blockade to reduce respiratory secretions
D. Inhibition of norepinephrine release at the synapse
Correct Answer: A
Explanation: Epinephrine is a non-selective adrenergic agonist that acts on Alpha-1, Beta-
1, and Beta-2 receptors. The Alpha-1 stimulation causes vasoconstriction to raise
dangerously low blood pressure during anaphylaxis. Simultaneously, Beta-2 stimulation
relaxes the smooth muscles in the lungs to open the airways. Beta-1 stimulation also
, provides cardiac support by increasing heart rate and contractility. This multi-receptor
approach makes it the gold standard for treating life-threatening allergic reactions.
6. Which drug is a selective Alpha-1 antagonist commonly used to treat hypertension and
benign prostatic hyperplasia (BPH)?
A. Prazosin
B. Clonidine
C. Propranolol
D. Metoprolol
Correct Answer: A
Explanation: Prazosin works by selectively blocking Alpha-1 receptors on vascular smooth
muscle and the bladder neck. This results in vasodilation, which effectively lowers systemic
blood pressure in hypertensive patients. In BPH, the relaxation of the smooth muscle in the
prostate and bladder neck improves urinary flow. Propranolol and Metoprolol are beta-
blockers and do not target the Alpha-1 receptor primarily. Patients should be warned about
the ‘first-dose effect’ which can cause significant orthostatic hypotension.
7. How does Clonidine exert its primary therapeutic effect in the management of
hypertension?
A. Stimulating peripheral Alpha-1 receptors
B. Blocking Beta-1 receptors in the heart
C. Stimulating central Alpha-2 receptors
D. Inhibiting the release of acetylcholine
Correct Answer: C
Explanation: Clonidine acts as a central Alpha-2 adrenergic agonist in the brainstem. By
stimulating these receptors, it reduces the sympathetic outflow from the central nervous
system to the peripheral vasculature. This leads to a decrease in heart rate and peripheral
vascular resistance, lowering blood pressure. It is not an antagonist like Prazosin or a
direct beta-blocker like Propranolol. Sudden discontinuation of Clonidine can cause
dangerous rebound hypertension due to a surge in catecholamines.
8. A patient with Myasthenia Gravis is treated with Neostigmine. What is the mechanism of
this drug?
A. It inhibits the enzyme acetylcholinesterase
B. It directly stimulates nicotinic receptors at the NMJ
C. It blocks muscarinic receptors to prevent tremors
D. It increases the reuptake of choline into the neuron
