ATI RN
Endocrine System Exam Questions Questions
Question 1 of 5
α-1 adrenergic receptors are selectively blocked by:
Correct Answer: B
Rationale: The correct answer is B: Prazosin. α-1 adrenergic receptors are selectively blocked by prazosin. Prazosin is a selective α-1 adrenergic receptor antagonist, specifically targeting these receptors. It works by blocking the effects of norepinephrine, leading to vasodilation and reduced blood pressure. A: Phentolamine is a non-selective α-adrenergic receptor antagonist, blocking both α-1 and α-2 receptors. C: Propranolol is a non-selective β-adrenergic receptor antagonist, blocking β-1 and β-2 receptors. D: Ergotamine is a medication used for the treatment of migraines and has vasoconstrictive properties but does not selectively block α-1 adrenergic receptors.
Question 2 of 5
Which of the following statements about anticholinesterase drugs is WRONG:
Correct Answer: D
Rationale: The correct answer is D because anticholinesterase drugs are not bronchodilators; they actually increase cholinergic activity by inhibiting the breakdown of acetylcholine. Reversible and irreversible types do exist (A), neostigmine and physostigmine are examples (B), and they can cause miosis and lacrimation due to increased cholinergic activity (C). Hence, D is the incorrect statement.
Question 3 of 5
A practical test to differentiate between myasthenia crisis and cholinergic crisis is by injecting the patient:
Correct Answer: C
Rationale: Rationale: Edrophonium is used to differentiate myasthenia crisis and cholinergic crisis by temporarily improving muscle weakness in myasthenia crisis but worsening symptoms in cholinergic crisis. Neostigmine (A) and Succinylcholine (D) can exacerbate cholinergic crisis. Hyoscine (B) is not used for this purpose.
Question 4 of 5
The neurotransmitter released at the end of most sympathetic nerve fibers is:
Correct Answer: B
Rationale: The correct answer is B: Noradrenaline. Sympathetic nerve fibers release noradrenaline as the primary neurotransmitter to activate the fight-or-flight response. Noradrenaline acts on adrenergic receptors to increase heart rate, blood pressure, and blood flow to muscles. Epinephrine (choice A) is also released in the sympathetic nervous system but mainly by the adrenal glands. Acetylcholine (choice C) is the primary neurotransmitter in the parasympathetic nervous system. Acetylcholinesterase (choice D) is an enzyme that breaks down acetylcholine and is not a neurotransmitter.
Question 5 of 5
We have an emergency clinical situation, which requires a drug to produce both bronchodilation and raise blood pressure. Which one of the following drugs can achieve these two goals?
Correct Answer: B
Rationale: Rationale: 1. Adrenaline is a non-selective adrenergic agonist that acts on both alpha and beta receptors. 2. Activation of beta-2 receptors in the lungs causes bronchodilation. 3. Activation of alpha-1 receptors in blood vessels raises blood pressure. 4. Atropine (A) is a muscarinic antagonist, not adrenergic. 5. Isoproterenol (C) primarily targets beta receptors, not alpha for blood pressure. 6. Noradrenaline (D) mainly acts on alpha receptors, not beta for bronchodilation.