USMLE Step 1 Pharmacology of the Autonomic Nervous
System 2026 | Questions & Answers | Graded A+
1. Describe the mechanism by which pilocarpine increases salivation in patients
with Sjogren's Syndrome.
Pilocarpine stimulates muscarinic receptors in the salivary glands,
leading to increased saliva production.
Pilocarpine blocks adrenergic receptors, reducing saliva production.
Pilocarpine directly stimulates nicotinic receptors in the nervous
system.
Pilocarpine inhibits acetylcholinesterase, increasing acetylcholine
levels in the blood.
2. What types of chemoreceptors are primarily involved in monitoring blood
CO2 levels during a sleep study?
Alpha and Beta adrenergic receptors
Peripheral chemoreceptors and Central chemoreceptors
Cholinergic receptors and Muscarinic receptors
Nicotinic receptors and Adrenergic receptors
3. What are the primary locations of the receptors that respond to oxygen
levels in the blood?
Carotid and Aortic Bodies
Heart
Lungs
Brainstem
,4. What is the name of the class of muscle relaxants that causes prolonged
muscle paralysis without depolarization?
Depolarizing neuromuscular blockers
Adrenergic antagonists
Non-depolarizing neuromuscular blockers
Cholinergic agonists
5. What is the name of the drug that acts as a depolarizing neuromuscular
blocker during intubation?
Vecuronium
Rocuronium
Atracurium
Succinylcholine
6. The treatment of choice for acute asthmatic episodes in children is:
an inhaled short-acting beta2-agonist
an oral leukotriene modifier
an inhaled long-acting beta2-agonist
an inhaled corticosteroid
an oral slow-release theophylline
7. In a clinical scenario where a patient with severe hypotension is administered
a high-dose sympathomimetic agent, what physiological response should be
anticipated regarding blood pressure?
Increased heart rate without a change in blood pressure.
, No change in blood pressure due to receptor desensitization.
Decreased diastolic blood pressure due to beta-2 receptor activation.
Increased diastolic blood pressure due to alpha-1 adrenergic
receptor activation.
8. Drugs that act as vasodilators to reduce hypertension can produce reflex
tachycardia as a side-effect. This is due to:
the parasympathetic nervous system gets triggered by the
vasodilation, and reflexively sends messages via the vagal nerves to
the heart to increase cardiac output and heart rate.
an increase in venous return to the heart
falling BP triggers baroreceptors in the aorta stimulating a
sympathetic nerve response in the heart
reflex vasoconstriction as a homeostatic response
9. A cholinergic medication used to treat patients with Sjogren's Syndrome is:
Benztropine
Pilocarpine
Atropine
Dicyclomine
10. Describe the role of methacholine in the diagnosis of asthma and how it
affects bronchial smooth muscle.
Methacholine is a beta-agonist that opens the airways in asthma
patients.
Methacholine is a corticosteroid used to reduce inflammation in
asthma.
, Methacholine is a direct cholinergic agonist that induces
bronchoconstriction, helping to assess airway hyperreactivity in
asthma patients.
Methacholine is an adrenergic antagonist that relaxes bronchial
smooth muscle.
11. What symptoms are indicative of poisoning from organophosphate
exposure?
Profuse vomiting, diarrhea, pinpoint pupils, and muscle weakness.
Dry mouth, dilated pupils, and increased heart rate.
Nausea, headache, and blurred vision.
Fever, rash, and joint pain.
12. In a patient undergoing surgery who has a history of myasthenia gravis,
which class of muscle relaxants would be most appropriate to use and why?
Adrenergic antagonists, to reduce muscle tone.
Non-depolarizing neuromuscular blockers, because they do not
exacerbate the condition by increasing acetylcholine levels.
Cholinergic agonists, to enhance neuromuscular transmission.
Depolarizing neuromuscular blockers, as they are more effective in
patients with myasthenia gravis.
13. What medication provides quick relief for a child who is wheezing and has
SOB after activity?
Theophylline
Montelukast (Singulair)
Budesonide (Pulmicort Flexhaler)
System 2026 | Questions & Answers | Graded A+
1. Describe the mechanism by which pilocarpine increases salivation in patients
with Sjogren's Syndrome.
Pilocarpine stimulates muscarinic receptors in the salivary glands,
leading to increased saliva production.
Pilocarpine blocks adrenergic receptors, reducing saliva production.
Pilocarpine directly stimulates nicotinic receptors in the nervous
system.
Pilocarpine inhibits acetylcholinesterase, increasing acetylcholine
levels in the blood.
2. What types of chemoreceptors are primarily involved in monitoring blood
CO2 levels during a sleep study?
Alpha and Beta adrenergic receptors
Peripheral chemoreceptors and Central chemoreceptors
Cholinergic receptors and Muscarinic receptors
Nicotinic receptors and Adrenergic receptors
3. What are the primary locations of the receptors that respond to oxygen
levels in the blood?
Carotid and Aortic Bodies
Heart
Lungs
Brainstem
,4. What is the name of the class of muscle relaxants that causes prolonged
muscle paralysis without depolarization?
Depolarizing neuromuscular blockers
Adrenergic antagonists
Non-depolarizing neuromuscular blockers
Cholinergic agonists
5. What is the name of the drug that acts as a depolarizing neuromuscular
blocker during intubation?
Vecuronium
Rocuronium
Atracurium
Succinylcholine
6. The treatment of choice for acute asthmatic episodes in children is:
an inhaled short-acting beta2-agonist
an oral leukotriene modifier
an inhaled long-acting beta2-agonist
an inhaled corticosteroid
an oral slow-release theophylline
7. In a clinical scenario where a patient with severe hypotension is administered
a high-dose sympathomimetic agent, what physiological response should be
anticipated regarding blood pressure?
Increased heart rate without a change in blood pressure.
, No change in blood pressure due to receptor desensitization.
Decreased diastolic blood pressure due to beta-2 receptor activation.
Increased diastolic blood pressure due to alpha-1 adrenergic
receptor activation.
8. Drugs that act as vasodilators to reduce hypertension can produce reflex
tachycardia as a side-effect. This is due to:
the parasympathetic nervous system gets triggered by the
vasodilation, and reflexively sends messages via the vagal nerves to
the heart to increase cardiac output and heart rate.
an increase in venous return to the heart
falling BP triggers baroreceptors in the aorta stimulating a
sympathetic nerve response in the heart
reflex vasoconstriction as a homeostatic response
9. A cholinergic medication used to treat patients with Sjogren's Syndrome is:
Benztropine
Pilocarpine
Atropine
Dicyclomine
10. Describe the role of methacholine in the diagnosis of asthma and how it
affects bronchial smooth muscle.
Methacholine is a beta-agonist that opens the airways in asthma
patients.
Methacholine is a corticosteroid used to reduce inflammation in
asthma.
, Methacholine is a direct cholinergic agonist that induces
bronchoconstriction, helping to assess airway hyperreactivity in
asthma patients.
Methacholine is an adrenergic antagonist that relaxes bronchial
smooth muscle.
11. What symptoms are indicative of poisoning from organophosphate
exposure?
Profuse vomiting, diarrhea, pinpoint pupils, and muscle weakness.
Dry mouth, dilated pupils, and increased heart rate.
Nausea, headache, and blurred vision.
Fever, rash, and joint pain.
12. In a patient undergoing surgery who has a history of myasthenia gravis,
which class of muscle relaxants would be most appropriate to use and why?
Adrenergic antagonists, to reduce muscle tone.
Non-depolarizing neuromuscular blockers, because they do not
exacerbate the condition by increasing acetylcholine levels.
Cholinergic agonists, to enhance neuromuscular transmission.
Depolarizing neuromuscular blockers, as they are more effective in
patients with myasthenia gravis.
13. What medication provides quick relief for a child who is wheezing and has
SOB after activity?
Theophylline
Montelukast (Singulair)
Budesonide (Pulmicort Flexhaler)
