ATI RN
Endocrine System Exam Questions Questions
Question 1 of 5
Concerning physostigmine, which of the following is CORRECT:
Correct Answer: D
Rationale: The correct answer is D because physostigmine is used in the treatment of glaucoma due to its ability to lower intraocular pressure. It works by inhibiting the enzyme acetylcholinesterase, leading to increased levels of acetylcholine which helps in constricting the pupil and improving drainage of fluid in the eye. Options A and C are incorrect as physostigmine is a tertiary amine and a reversible anti-cholinesterase. Option B is incorrect as physostigmine does have CNS action, crossing the blood-brain barrier and affecting brain function.
Question 2 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 3 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 4 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.
Question 5 of 5
Neostigmine is a drug useful in the treatment of myasthenia gravis, but it causes parasympathomimetic effects unless another drug is given first. This drug is:
Correct Answer: A
Rationale: The correct answer is A: Atropine. Neostigmine is a cholinesterase inhibitor that increases acetylcholine levels leading to parasympathomimetic effects. Atropine, an anticholinergic drug, blocks the effects of acetylcholine, preventing excessive stimulation of cholinergic receptors. Administering atropine before neostigmine helps counteract the parasympathomimetic effects, making it a necessary pre-treatment. Epinephrine and isoproterenol are adrenergic drugs and wouldn't counteract the cholinergic effects of neostigmine. Edrophonium is another cholinesterase inhibitor like neostigmine, so it wouldn't be effective in preventing the parasympathomimetic effects.